Cisco IOS Commands

If you have added, deleted, or modified VLAN parameters in VLAN database mode but you do not want to keep the changes, the abort command causes all the changes to be abandoned. The VLAN configuration that was running before you entered VLAN database mode continues to be used.

Examples

The following example shows how to abandon the proposed new VLAN database and exit to the privileged EXEC mode:

Switch(vlan)# abort
Switch#

You can verify that no VLAN database changes occurred by entering the show vlan brief command in privileged EXEC mode.

Related Commands

Command Description

apply

Implements the proposed new VLAN database, increments the database configuration revision number, propagates it throughout the administrative domain, and remains in VLAN database mode.

exit

Implements the proposed new VLAN database, increments the database configuration number, propagates it throughout the administrative domain, and returns to privileged EXEC mode.

reset

Abandons the proposed VLAN database and remains in VLAN database mode. Resets the proposed database to the currently implemented VLAN database on the switch.

show vlan

Displays the parameters for all configured VLANs in the administrative domain.

shutdown vlan

Shuts down (suspends) local traffic on the specified VLAN.

vlan database

Enters VLAN database mode from the command-line interface (CLI).

Command	Description
apply	Implements the proposed new VLAN database, increments the database configuration revision number, propagates it throughout the administrative domain, and remains in VLAN database mode.
exit	Implements the proposed new VLAN database, increments the database configuration number, propagates it throughout the administrative domain, and returns to privileged EXEC mode.
reset	Abandons the proposed VLAN database and remains in VLAN database mode. Resets the proposed database to the currently implemented VLAN database on the switch.
show vlan	Displays the parameters for all configured VLANs in the administrative domain.
shutdown vlan	Shuts down (suspends) local traffic on the specified VLAN.
vlan database	Enters VLAN database mode from the command-line interface (CLI).

apply

Use the apply VLAN database command to implement the proposed new VLAN database, increment the database configuration revision number, propagate it throughout the administrative domain, and remain in VLAN database mode.

apply

Syntax Description

This command has no arguments or keywords.

Defaults

No default is defined.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Release	Modification
11.2(8)SA4	This command was first introduced.

Usage Guidelines

The apply command implements the configuration changes you made after you entered VLAN database mode and uses them for the running configuration. This command keeps you in VLAN database mode.

You cannot use this command when the switch is in the VLAN Trunk Protocol (VTP) client mode.

Examples

The following example shows how to implement the proposed new VLAN database and recognize it as the current database:

Switch(vlan)# apply

You can verify that VLAN database changes occurred by entering the show vlan command in privileged EXEC mode.

Command	Description
apply	Implements the proposed new VLAN database, increments the database configuration revision number, propagates it throughout the administrative domain, and remains in VLAN database mode.
exit	Implements the proposed new VLAN database, increments the database configuration number, propagates it throughout the administrative domain, and returns to privileged EXEC mode.
reset	Abandons the proposed VLAN database and remains in VLAN database mode. Resets the proposed database to the currently implemented VLAN database on the switch.
show vlan	Displays the parameters for all configured VLANs in the administrative domain.
shutdown vlan	Shuts down (suspends) local traffic on the specified VLAN.
vlan database	Enters VLAN database mode from the command-line interface (CLI).

cgmp

Use the cgmp global configuration command to enable Cisco Group Management Protocol (CGMP) and other CGMP options. Use the no form of this command to disable CGMP and its options.

cgmp {leave-processing | holdtime time | reserved}

no cgmp {leave-processing | holdtime | reserved}

Syntax Description

leave-processing

Enable Fast Leave processing on the switch.

holdtime time

Number of seconds a router connection is retained before the switch ceases to exchange messages with it. You can enter a number from 10 to 6000 (seconds).

reserved

Allow reserved addresses from 0100.5E00.0000 to 0100.5E00.00FF to join as group destination addresses.

leave-processing	Enable Fast Leave processing on the switch.
holdtime time	Number of seconds a router connection is retained before the switch ceases to exchange messages with it. You can enter a number from 10 to 6000 (seconds).
reserved	Allow reserved addresses from 0100.5E00.0000 to 0100.5E00.00FF to join as group destination addresses.

Defaults

CGMP is enabled.

Fast Leave is disabled.

The hold time is 300 seconds.

Reserved addresses are allowed as group destination addresses.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

12.0(5)XP

The reserved keyword was added.

Release	Modification
11.2(8)SA3	This command was first introduced.
12.0(5)XP	The reserved keyword was added.

Usage Guidelines

CGMP must be enabled before the Fast Leave option can be enabled.

Examples

The following example shows how to disable CGMP:

Switch(config)# no cgmp

The following example shows how to disable the Fast Leave option:

Switch(config)# no cgmp leave-processing

The following example shows how to set 400 seconds as the length of time the switch waits before ceasing to exchange messages with a router:

Switch(config)# cgmp holdtime 400

The following example shows how to remove the amount of time the switch waits before ceasing to exchange messages with a router:

Switch(config)# no cgmp holdtime

The following example shows how to exclude reserved addresses from the group destination address for compatibility with Catalyst 5000 series switches.

Switch(config)# no cgmp reserved

You can verify the previous commands by entering the show cgmp command in privileged EXEC mode.

Related Commands

Command Description

clear cgmp

Deletes information that was learned by the switch using the CGMP.

show cgmp

Displays the current state of the CGMP-learned multicast groups and routers.

Command	Description
clear cgmp	Deletes information that was learned by the switch using the CGMP.
show cgmp	Displays the current state of the CGMP-learned multicast groups and routers.

clear cgmp

Use the clear cgmp privileged EXEC command to delete information that was learned by the switch using the Cisco Group Management Protocol (CGMP).

clear cgmp [vlan vlan-id] | [group [address] | router [address]]

Syntax Description

vlan vlan-id

(Optional) VLAN for which the CGMP groups or routers are to be deleted. Valid IDs are from 1 to 1001; do not enter leading zeroes.

group address

Delete all known multicast groups and their destination ports. Limited to a VLAN if the vlan keyword is entered. Limited to a specific group if the address parameter (MAC address of the group or router) is entered.

router address

(Optional) Delete all routers, their ports, and expiration times. Limited to a given VLAN if the vlan keyword is entered. Limited to a specific router if the address parameter is entered.

vlan vlan-id	(Optional) VLAN for which the CGMP groups or routers are to be deleted. Valid IDs are from 1 to 1001; do not enter leading zeroes.
group address	Delete all known multicast groups and their destination ports. Limited to a VLAN if the vlan keyword is entered. Limited to a specific group if the address parameter (MAC address of the group or router) is entered.
router address	(Optional) Delete all routers, their ports, and expiration times. Limited to a given VLAN if the vlan keyword is entered. Limited to a specific router if the address parameter is entered.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Release	Modification
11.2(8)SA3	This command was first introduced.

Usage Guidelines

Using clear cgmp with no arguments deletes all groups and routers in all VLANs.

Examples

The following example shows how to delete all groups and routers on VLAN 2:

Switch# clear cgmp vlan 2

The following example shows how to delete all groups on all VLANs:

Switch# clear cgmp group

The following example shows how to delete a router address on VLAN 2:

Switch# clear cgmp vlan 2 router 0012.1234.1234

You can verify the previous commands by entering the show cgmp command in privileged EXEC mode.

Related Commands

Command Description

cgmp

Enables CGMP and the Fast Leave option and sets the router port aging time.

show cgmp

Displays the current state of the CGMP-learned multicast groups and routers.

Command	Description
cgmp	Enables CGMP and the Fast Leave option and sets the router port aging time.
show cgmp	Displays the current state of the CGMP-learned multicast groups and routers.

clear ip address

Use the clear ip address privileged EXEC command to delete an IP address for a switch without disabling the IP processing.

clear ip address [vlan vlan-id]

Syntax Description

vlan vlan-id

(Optional) Delete an IP address only within the specified VLAN.
Valid IDs are from 1 to 1000; do not enter leading zeroes.

vlan vlan-id	(Optional) Delete an IP address only within the specified VLAN. Valid IDs are from 1 to 1000; do not enter leading zeroes.

Defaults

No IP address is defined for the switch.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA

This command was first introduced.

11.2(8)SA3

The vlan keyword was added.

Release	Modification
11.2(8)SA	This command was first introduced.
11.2(8)SA3	The vlan keyword was added.

Usage Guidelines

A switch can have one IP address.

The IP address of the switch can be accessed only by nodes connected to ports that belong to the management VLAN. By default, the management VLAN is VLAN 1, but you can configure a different VLAN as the management VLAN.

If your switch receives its IP address from a BOOTP server and you clear the switch IP address by using the clear ip address command, the BOOTP server reassigns it.

Examples

The following example shows how to clear the IP address for the switch on VLAN 1:

Switch# clear ip address vlan 1

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the configuration information currently running on the switch.

Command	Description
show running-config	Displays the configuration information currently running on the switch.

clear mac-address-table

Use the clear mac-address-table privileged EXEC command to delete entries from the MAC address table.

clear mac-address-table [static | dynamic | secure] [address hw-addr] [interface interface]
[atm slot/port] [vlan vlan-id]

Syntax Description

static

(Optional) Delete only static addresses.

dynamic

(Optional) Delete only dynamic addresses.

secure

(Optional) Delete only secure addresses.

address hw-addr

(Optional) Delete the address hw-addr of type static, dynamic, and secure as specified.

interface interface

(Optional) Delete an address on the interface interface of type static, dynamic, or secure as specified.

atm slot/port

(Optional) Delete only ATM addresses on this slot and port.

vlan vlan-id

(Optional) Delete all the MAC addresses for vlan-id. Valid IDs are from
1 to 1005; do not enter leading zeroes.

static	(Optional) Delete only static addresses.
dynamic	(Optional) Delete only dynamic addresses.
secure	(Optional) Delete only secure addresses.
address hw-addr	(Optional) Delete the address hw-addr of type static, dynamic, and secure as specified.
interface interface	(Optional) Delete an address on the interface interface of type static, dynamic, or secure as specified.
atm slot/port	(Optional) Delete only ATM addresses on this slot and port.
vlan vlan-id	(Optional) Delete all the MAC addresses for vlan-id. Valid IDs are from 1 to 1005; do not enter leading zeroes.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA

This command was first introduced.

11.2(8)SA3

The vlan keyword was added.

11.2(8)SA5

The atm keyword was added.

Release	Modification
11.2(8)SA	This command was first introduced.
11.2(8)SA3	The vlan keyword was added.
11.2(8)SA5	The atm keyword was added.

Usage Guidelines

This command deletes entries from the global MAC address table. Specific subsets can be deleted by using the optional keywords and values. If more than one optional keyword is used, all of the conditions in the argument must be true for that entry to be deleted.

Examples

The following example shows how to delete static addresses on port fa0/7:

Switch# clear mac-address-table static interface fa0/7

The following example shows how to delete all secure addresses in VLAN 3:

Switch# clear mac-address-table secure vlan 3

The following example shows how to delete address 0099.7766.5544 from all ports in all VLANs. If the address exists in multiple VLANs or multiple ports, all the instances are deleted.

Switch# clear mac-address-table address 0099.7766.5544

The following example shows how to delete address 0099.7766.5544 only in VLAN 2:

Switch# clear mac-address-table address 0099.7766.5544 vlan 2

The following example shows how to delete the secure MAC address 00c0.00a0.03fa associated with the ATM port in expansion slot 2:

Switch(config)# clear mac-address-table secure 00c0.00a0.03fa atm 2/1

The following example shows how to delete the static address 00c0.00a0.03fa associated with the ATM port in expansion slot 2:

Switch(config)# clear mac-address-table static 00c0.00a0.03fa atm 2/1

You can verify the previous commands by entering the show mac-address-table command in privileged EXEC mode.

Related Commands

Command Description

show mac-address-table

Displays the MAC address table.

Command	Description
show mac-address-table	Displays the MAC address table.

clear vmps statistics

Use the clear vmps statistics privileged EXEC command to clear the statistics maintained by the VLAN Query Protocol (VQP) client.

clear vmps statistics

Syntax Description

This command has no arguments or keywords.

Defaults

No default is defined.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Release	Modification
11.2(8)SA4	This command was first introduced.

Examples

The following example shows how to clear VLAN Membership Policy Server (VMPS) statistics:

Switch# clear vmps statistics

You can verify the previous command by entering the show vmps statistics command in privileged EXEC mode.

Related Commands

Command Description

show vmps statistics

Displays the VLAN Query Protocol (VQP) version, reconfirmation interval, retry count, VMPS IP addresses, and the current and primary servers.

Command	Description
show vmps statistics	Displays the VLAN Query Protocol (VQP) version, reconfirmation interval, retry count, VMPS IP addresses, and the current and primary servers.

clear vtp counters

Use the clear vtp counters privileged EXEC command to clear the VLAN Trunk Protocol (VTP) and pruning counters.

clear vtp counters

Syntax Description

This command has no arguments or keywords.

Defaults

No default is defined.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Release	Modification
11.2(8)SA4	This command was first introduced.

Examples

The following example shows how to clear the VTP counters:

Switch# clear vtp counters

You can verify the previous command by entering the show vtp counters command in privileged EXEC mode.

Related Commands

Command Description

show vtp counters

Display general information about the VTP management domain, status, and counters.

Command	Description
show vtp counters	Display general information about the VTP management domain, status, and counters.

cluster commander-address

The command switch automatically provides its MAC address to member switches when these switches join the cluster. The member switch adds this information and other cluster information to its running configuration file. You do not need to enter this command. Enter the no form of this global configuration command on a member switch to remove it from a cluster only during debugging or recovery procedures.

cluster commander-address mac-address member number name name

no cluster commander-address

default cluster commander-address

Syntax Description

mac-address

MAC address of the cluster command switch.

member number

Number of member switch. The range is from 0 to 15.

name name

Name of the cluster up to 31 characters.

no

Remove a switch from the cluster. Entered on the member switch.

default

Remove a switch from the cluster. Entered on the member switch.

mac-address	MAC address of the cluster command switch.
member number	Number of member switch. The range is from 0 to 15.
name name	Name of the cluster up to 31 characters.
no	Remove a switch from the cluster. Entered on the member switch.
default	Remove a switch from the cluster. Entered on the member switch.

Defaults

The switch is not a member of any cluster.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

12.0(5)XU

The member and name keywords were added.

Release	Modification
11.2(8)SA6	This command was first introduced.
12.0(5)XU	The member and name keywords were added.

Usage Guidelines

A cluster member can have only one command switch.

The member switch retains the identity of the command switch during a system reload by using the mac-address parameter.

You can enter the no form on a member switch to remove it from the cluster only during debugging or recovery procedures. However, with normal switch configuration, we recommend that you remove member switches only by entering the no cluster member n command on the command switch.

When a standby command switch becomes active, it removes the cluster commander-address line from its configuration.

Examples

The following is sample text from the running configuration of a cluster member.

Switch(config)# cluster commander-address 00e0.9bc0.a500 member 4 name my_cluster

The following example shows how to remove a member from the cluster by using the cluster member console.

Switch-es3# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Switch-es3(config)# no cluster commander-address

You can verify the previous command by entering the show cluster command in user EXEC mode.

Related Commands

Command Description

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

Command	Description
show cluster	Displays the cluster status and a summary of the cluster to which the switch belongs.

cluster discovery hop-count

Use the cluster discovery hop-count global configuration command on the command switch to set the hop-count limit for extended discovery of candidate switches. Use the no form of this command to set the hop count to the default value.

cluster discovery hop-count number

no cluster discovery hop-count

default cluster discovery hop-count

Syntax Description

number

Number of hops from the cluster edge that the command switch limits the discovery of candidates. The range is from 1 to 7.

no

Set the hop count to the default value (3).

default

Set the hop count to the default value (3).

number	Number of hops from the cluster edge that the command switch limits the discovery of candidates. The range is from 1 to 7.
no	Set the hop count to the default value (3).
default	Set the hop count to the default value (3).

Defaults

The hop count is set to 3.

Command Modes

Global configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Release	Modification
12.0(5)XU	This command was first introduced.

Usage Guidelines

Enter this command only on the command switch. This command does not operate on member switches.

If the hop count is set to 1, it disables extended discovery. The command switch discovers only candidates that are one hop from the edge of the cluster. The edge of the cluster is the point between the last discovered member switch and the first discovered candidate switch.

Examples

The following example shows how to set hop count limit to 4. This command is executed on the command switch.

Switch(config)# cluster discovery hop-count 4

You can verify the previous command by entering the show cluster command in user EXEC mode.

Related Commands

Command Description

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

show cluster candidates

Displays a list of candidate switches.

cluster enable

Use the cluster enable global configuration command on a command-capable switch to enable it as the cluster command switch, assign a cluster name, and optionally assign a member number to it. Use the no form of the command to remove all members and make the command switch a candidate switch.

cluster enable name [command-switch-member-number]

no cluster enable

default cluster enable

Syntax Description

name

Name of the cluster up to 31 characters. Valid characters include only alphanumerics, dashes, and underscores.

command-switch-member-number

(Optional) Assign a member number to the command switch of the cluster. The range is from 0 to 15.

no

Remove all member switches and make the command switch a candidate.

default

Switch is not a command switch.

Defaults

The switch is not a command switch.

No cluster name is defined.

The member number is 0 when this is the command switch.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

12.0(5)XU

The command-switch-member-number variable was added.

Usage Guidelines

This command runs on any command-capable switch that is not part of any cluster. This command fails if a device is already configured as a member of the cluster.

You must name the cluster when you enable the command switch. If the switch is already configured as the command switch, this command changes the cluster name if it is different from the previous name.

Examples

The following example shows how to enable the command switch, name the cluster, and set the command switch member number to 4.

Switch(config)# cluster enable Engineering-IDF4 4

You can verify the previous command by entering the show cluster command in user EXEC mode on the command switch.

Related Commands

Command Description

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

cluster holdtime

Use the cluster holdtime global configuration command on the command switch to set the duration in seconds before a switch (either the command or member switch) declares the other switch down after not receiving heartbeat messages. Use the no form of this command to set the duration to the default value.

cluster holdtime holdtime-in-secs

no cluster holdtime

default cluster holdtime

Syntax Description

holdtime-in-secs

Duration in seconds before a switch (either a command or member switch) declares the other switch down. The range is from 1 to 300 seconds

no

Set the holdtime to the default value (80 seconds).

default

Set the holdtime to the default value (80 seconds)

Defaults

The holdtime is 80 seconds.

Command Modes

Global configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

Use this command with the cluster timer global configuration command only on the command switch. The command switch propagates the values to all its cluster members.

The holdtime is typically set as a multiple of the interval timer (cluster timer). For example, it takes (holdtime-in-secs divided by interval-in-secs) number of heartbeat messages to be missed in a row to declare a switch down.

Examples

The following example shows how to change the interval timer and the duration on the command switch.

Switch(config)# cluster timer 3
Switch(config)# cluster holdtime 30

You can verify the previous commands by entering the show cluster command in user EXEC mode.

Related Commands

Command Description

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

cluster management-vlan

Use the cluster management-vlan global configuration command on the command switch to change the management VLAN for the entire cluster. Use the no form of this command to change the management VLAN to VLAN 1.

cluster management-vlan n

no cluster management-vlan

default cluster management-vlan

Syntax Description

n

VLAN ID of the new management VLAN. Valid VLAN IDs are from 1 to 1001.

no

Set the management VLAN to VLAN 1

default

Set the management VLAN to VLAN 1

Defaults

The default management VLAN is VLAN 1.

Command Modes

Global configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

Enter this command only on the command switch.

This command is not written to the configuration file.

Examples

The following example shows how to change the management VLAN to VLAN 5 on the entire cluster.

Switch(config)# cluster management-vlan 5

You can verify the previous command by entering the show interface vlan number command in privileged EXEC mode.

Related Commands

Command Description

management

Shuts down the current management VLAN interface and enables the new management VLAN interface on an individual switch.

cluster member

Use the cluster member global configuration command on the command switch to add members to a cluster. Use the no form of the command to remove members from the cluster.

cluster member [n] mac-address H.H.H [password enable-password]

no cluster member n

default cluster member n

Syntax Description

n

(Optional) The number that identifies a cluster member. The range is from 0 to 15

mac-address H.H.H

MAC address of the member switch in hexadecimal format.

password enable-password

Enable password of the candidate switch. The password is not required if there is no password on the candidate switch.

no

Remove the specified member from the cluster.

default

Remove the specified member from the cluster.

Defaults

A newly enabled command switch has no associated cluster members.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Enter this command only on the command switch to add a member to or remove a member from the cluster. If a switch is not commanding a cluster, this command displays an error message.

You do not need to enter a member number. The command switch selects the next available member number and assigns it to the switch joining the cluster.

You must enter the enable password of the candidate switch for authentication when it joins the cluster. The password is not saved in the running or startup configuration. After a candidate switch becomes a member of the cluster, its password becomes the same as the command-switch password.

If a switch does not have a configured host name, the command switch appends a member number to the command-switch host name and assigns it to the member switch.

Examples

The following example shows how to add a switch as member 2 with MAC address 00E0.1E00.2222 and the password grandkey to a cluster.

Switch(config)# cluster member 2 mac-address 00E0.1E00.2222 password grandkey

The following example shows how to add a switch with MAC address 00E0.1E00.3333 to the cluster. The command switch selects the next available member number and assigns it to the switch joining the cluster.

Switch(config)# cluster member mac-address 00E0.1E00.3333

You can verify the previous command by entering the show cluster members command in user EXEC mode on the command switch.

cluster run

Use the cluster run global configuration command to enable clustering on a switch. Use the no form of this command to disable clustering on a switch.

cluster run

no cluster run

default cluster run

Syntax Description

no

Disable clustering on a switch.

default

Enable clustering on a switch.

Defaults

Clustering is enabled on all switches.

Command Modes

Global configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

When you enter the no cluster run command on a command switch, the command switch is disabled.

When you enter the no cluster run command on a member switch, it is removed from the cluster.

When you enter the no cluster run command on a switch, it disables clustering on that switch. This switch is then incapable of becoming a candidate switch.

Examples

The following example shows how to disable clustering on the command switch:

Switch(config)# no cluster run

You can verify the previous command by entering the show cluster command in user EXEC mode.

Related Commands

Command Description

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

cluster setup

Use the cluster setup privileged EXEC command on the command switch to automatically build a cluster.

cluster setup

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

You can use the cluster setup command to add new switches to an existing cluster. The cluster setup command provides a high-level view of the configuration and guides you through the configuration change process. You can only see candidate switches that are one hop away from the command switch and have no IP address. To see devices farther away, use the show cluster members or show cluster candidates command.

If a candidate switch has a password, this information will not be passed to the cluster.

Examples

The following is an example of the cluster setup command output:

Switch# cluster setup
 
         --- Cluster Configuration Dialog ---
 
At any point you may enter a question mark '?' for help.
Use ctrl-c to abort configuration dialog at any prompt.
Default settings are in square brackets '[]'.
 
This switch is already configured as cluster command switch:
Command Switch Name:m217, contains 7 members
 
Continue with cluster configuration dialog? [yes/no]:yes
The suggested Cluster configuration is as follows:
 
                                                |---Upstream---|
SN MAC Address    Name         PortIf FEC Hops   SN PortIf  FEC  State
0  00d0.796d.2f00 Tahiti-24                0                     Cmdr    
1  00d0.7960.66c0 Wailea       Gi0/4       1     0  Gi0/1        Up      
2  00d0.7961.c4c0 Tahiti-12    Fa0/3       1     0  Fa0/13       Up      
3  00e0.1e9f.8300 Balboa       Fa0/11      2     2  Fa0/12       Up      
4  00e0.1e9f.7a00 Surfers-24   Fa0/5       1     0  Fa0/3        Up      
5  00e0.1e9f.8c00 Surfers-12-2 Fa0/4       1     0  Fa0/7        Up      
6  00e0.1e9f.8c40 Surfers-12-1 Fa0/1       1     0  Fa0/9        Up      
7* 0010.7bb6.1cc0 Ventura      Fa2/1       3     3  Fa0/24       Candidat 
 
 
The following configuration command script was created:
cluster member 7 mac-address 0010.7bb6.1cc0
!
end 
 
Use this configuration? [yes/no]:yes
 
Building configuration...
[OK]
Use the enabled mode 'configure' command to modify this configuration.
 
Switch#

Related Commands

Command Description

cluster enable

Enables a switch as the cluster command switch, assigns a cluster name, and optionally assigns a member number to it.

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

show cluster candidates

Displays a list of candidate switches.

show cluster members

Displays information about the cluster members.

cluster standby-group

Use the cluster standby-group global configuration command to enable command switch redundancy by binding the Hot Standby Router Protocol (HSRP) standby group to the cluster. Use the no form of this command to unbind the cluster from the HSRP standby group.

cluster standby-group HSRP-group-name

no cluster standby-group

default cluster standby-group

Syntax Description

HSRP-group-name

Name of the HSRP group that is bound to the cluster. The group name is limited to 32 characters.

no

Unbind the cluster from the HSRP standby group.

default

Unbind the cluster from the HSRP standby group.

Defaults

The cluster is not bound to any HSRP group.

Command Modes

Global configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

You must enter this command only on the command switch. If you enter it on a member switch, an error message appears.

The command switch propagates the cluster-HSRP binding information to all members. Each member switch stores the binding information in its nonvolatile RAM (NVRAM).

The HSRP group name must be a valid standby group; otherwise, the command exits with an error.

Examples

The following example shows how to bind the HSRP group named my_hsrp to the cluster. This command is executed on the command switch.

Switch(config)# cluster standby-group my_hsrp

The following example shows the error message when this command is executed on a command switch and the specified HSRP standby group does not exist:

Switch(config)# cluster standby-group my_hsrp
%ERROR: Standby group `my_hsrp' doesn't exist

The following example shows the error message when this command is executed on a member switch.

Switch(config)# cluster standby-group my_hsrp
%ERROR: This command runs only on the command switch

You can verify the previous commands by entering the show cluster command in user EXEC mode.

Related Commands

Command Description

standby ip

Enables HSRP on the interface.

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

show standby

Displays standby group information.

cluster timer

Use the cluster timer global configuration command on the command switch to set the interval in seconds between heartbeat messages. Use the no form of this command to set the interval to the default value.

cluster timer interval-in-secs

no cluster timer

default cluster timer

Syntax Description

interval-in-secs

Interval in seconds between heartbeat messages. The range is from
1 to 300 seconds.

no

Set the interval to the default value (8 seconds).

default

Set the interval to the default value (8 seconds).

Defaults

The interval is 8 seconds.

Command Modes

Global configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

Use this command with the cluster holdtime global configuration command only on the command switch. The command switch propagates the values to all its cluster members.

The holdtime is typically set as a multiple of the heartbeat interval timer (cluster timer). For example, it takes (holdtime-in-secs divided by the interval-in-secs) number of heartbeat messages to be missed in a row to declare a switch down.

Examples

The following example shows how to change the heartbeat interval timer and the duration on the command switch.

Switch(config)# cluster timer 3
Switch(config)# cluster holdtime 30

You can verify the previous commands by entering the show cluster command in user EXEC mode.

Related Commands

Command Description

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

delete

Use the delete privileged EXEC command to delete a file from the file system.

delete [device:]filename

Syntax Description

device:

Device containing the file to be deleted. Valid devices include the switch Flash memory and ATM module files. To access the ATM module, specify the slot number (1 or 2).

filename

Name of file.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

A colon (:) follows the device variable. Do not enter spaces after the colon.

Examples

The following example shows how to delete the file atm_image from the file system for an ATM
module installed in slot 1:

Switch# delete slot1:atm_image

The following example shows how to delete a file from the switch Flash memory:

Switch# delete flash:filename

Related Commands

Command Description

copy tftp

Downloads a file from a TFTP server to a device.

duplex

Use the duplex interface configuration command to specify the duplex mode of operation for Fast Ethernet and Gigabit Ethernet ports. Use the no form of this command to return the port to its default value.

duplex {full | half | auto}

no duplex

Syntax Description

full

Port is in full-duplex mode.

half

Port is in half-duplex mode.

auto

Port automatically detects whether it should run in full- or half-duplex mode.

Defaults

The default is auto.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines

Certain ports can be configured to be either full duplex or half duplex. Applicability of this command depends on the device to which the switch is attached.

For Fast Ethernet ports, setting the port to auto has the same effect as specifying half if the attached device does not autonegotiate the duplex parameter.

For Gigabit Ethernet ports, setting the port to auto has the same effect as specifying full if the attached device does not autonegotiate the duplex parameter.

If the speed is set to auto, the switch negotiates with the device at the other end of the link for the speed setting and then forces the speed setting to the negotiated value. The duplex setting remains as configured on each end of the link, which could result in a duplex setting mismatch.

If both the speed and duplex are set to specific values, autonegotiation is disabled.

Note For guidelines on setting the switch speed and duplex parameters, see the Catalyst 2900 Series XL Installation Guide and the Catalyst 3500 Series XL Installation Guide.

This command is not supported on the ATM module.

Examples

The following example shows how to set port 1 on a Fast Ethernet module installed in slot 2 to full duplex:

Switch(config)# interface fastethernet2/1
Switch(config-if)# duplex full

The following example shows how to set port 1 on a Gigabit Ethernet module installed in slot 2 to full duplex:

Switch(config)# interface gigabitethernet2/1
Switch(config-if)# duplex full

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

speed

Specifies the speed of a Fast Ethernet port.

enable last-resort

Use the enable last-resort global configuration command to specify what happens if the Terminal Access Controller Access Control System (TACACS) and Extended TACACS servers used by the enable command do not respond. Use the no form of this command to restore the default.

enable last-resort {password | succeed}

no enable last-resort

Syntax Description

password

Provide access to enable mode with entry of the privileged command level password. A password must contain from 1 to 25 uppercase and lowercase alphanumeric characters.

succeed

Provide access to enable mode without further question.

Defaults

Authentication is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

This secondary authentication is used only if the first attempt fails.

Note This command is not used with Terminal Access Controller Access Control System Plus (TACACS+), a Cisco proprietary protocol that instead uses the authentication, authorization, and accounting (AAA) suite of commands.

Examples

In the following example, if the TACACS servers do not respond to the enable command, you can enable access by entering the privileged-level password:

Switch(config)# enable last-resort <password>

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

enable

Accesses privileged EXEC mode.

show running-config

Displays the running configuration on the switch.

enable use-tacacs

Use the enable use-tacacs global configuration command to enable the use of Terminal Access Controller Access Control System (TACACS) to determine whether a user can access the privileged command level. Use the no form of this command to disable TACACS verification.

enable use-tacacs

no enable use-tacacs

Tips If you use the enable use-tacacs command, you must also use the tacacs-server authenticate enable command, or you will be locked out of the privileged command level.

Syntax Description

This command has no arguments or keywords.

Defaults

TACACS verification is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

When you add this command to the configuration file, the enable privilege EXEC command prompts for a new username and password. This pair is then passed to the TACACS server for authentication. If you are using Extended TACACS, it also sends any existing UNIX user identification code to the server.

Note This command initializes TACACS. Use the tacacs server-extended command to initialize Extended TACACS or use the aaa new-model command to initialize authentication, authorization, and accounting (AAA) and Terminal Access Controller Access Control System Plus (TACACS+).

Examples

The following example sets TACACS verification on the privileged EXEC login sequence:

Switch(config)# enable use-tacacs
Switch(config)# tacacs-server authenticate enable

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

tacacs-server authenticate enable

Indicates whether users can perform an attempted action under TACACS and extended TACACS.

exit

Use the exit VLAN database command to implement the proposed new VLAN database, increment the database configuration number, propagate it throughout the administrative domain, and return to privileged EXEC mode.

exit

Syntax Description

This command has no arguments or keywords.

Defaults

No default is defined.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

The exit command implements all the configuration changes you made since you entered VLAN database mode and uses them for the running configuration. This command returns you to privileged EXEC mode.

Examples

The following example shows how to implement the proposed new VLAN database and exit to privileged EXEC mode:

Switch(vlan)# exit
Switch#

You can verify the previous command by entering the show vlan brief command in privileged EXEC mode.

Related Commands

Command Description

abort

Abandons the proposed new VLAN database, exits VLAN database mode, and returns to privileged EXEC mode.

apply

Implements the proposed new VLAN database, increments the database configuration revision number, propagates it throughout the administrative domain, and remains in VLAN database mode.

reset

Abandons the proposed VLAN database and remains in VLAN database mode. Resets the proposed database to the currently implemented VLAN database on the switch.

show vlan

Displays the parameters for all configured VLANs in the administrative domain.

shutdown vlan

Shuts down (suspends) local traffic on the specified VLAN.

vlan database

Enters VLAN database mode from the command-line interface (CLI).

flowcontrol

Use the flowcontrol interface configuration command on Gigabit Ethernet ports to control traffic rates during congestion. Use the no form of this command to disable flow control on the port.

flowcontrol {asymmetric | symmetric}

no flowcontrol

Syntax Description

asymmetric

Enable the local port to perform flow control of the remote port. If the local port is congested, it can request the remote port to stop transmitting. When the congestion clears, the local port requests that the remote port begin transmitting.

symmetric

Enable the local port to perform flow control only if the remote port can also perform flow control of the local port. If the remote port cannot perform flow control, the local port also does not.

Defaults

The default is asymmetric.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Examples

The following example shows how to configure the local port to support any level of flow control by the remote port:

Switch(config-if)# flowcontrol

The following example shows how to configure the local port to control the traffic flow from the remote port:

Switch(config-if)# flowcontrol asymmetric

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show interface [interface-id] flow-control

Displays flowcontrol information for the specified port.

interface

Use the interface global configuration command to configure an interface type, create a switch virtual interface to be used as the management VLAN interface, and to enter interface configuration mode.

interface type slot/port | vlan number

no interface type slot/port | vlan number

Syntax Description

type

Type of interface to be configured. Can be Fast Ethernet, Gigabit Ethernet, or Asynchronous Transfer Mode (ATM).

slot

Slot number (0, 1, or 2). For an ATM module, use slot number 1 or 2.

port

Port ID.

vlan number

VLAN number from 1 to 1001 to be used as the management VLAN. Do not enter leading zeroes.

Defaults

The default management VLAN interface is VLAN 1.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

11.2(8)SA3

The vlan keyword was added.

Usage Guidelines

When creating a management VLAN interface, a space between vlan and number is accepted.

Only one management VLAN interface can be active.

You cannot delete the management VLAN 1 interface.

Before bringing up a new management VLAN interface with the no shutdown command, you must issue the shutdown command to disable the old one.

You can use the management command to shut down the active management VLAN interface and to enable the newly created management VLAN interface.

You can configure the management VLAN interface on static-access, multi-VLAN, dynamic-access, and trunk ports.

Examples

The following example shows how to enable the switch to act on ATM interface 1/2:

Switch(config)# interface atm 1/2
Switch(config-if)#

The following example shows how to change the management VLAN from VLAN 1 to VLAN 3. This series of commands should only be executed from the console. If these commands are executed through a Telnet session, the shutdown command disconnects the session, and there is no way to use IP to access the system.

Switch# configure terminal
Switch(config)# interface vlan 3
Switch(config-subif)# ip address 172.20.128.176 255.255.255.0
Switch(config-subif)# exit
Switch(config-if)# exit
Switch(config)# interface vlan 1
Switch(config-subif)# shutdown
Switch(config-subif)# exit
Switch(config-if)# exit
Switch(config)# interface vlan 3
Switch(config-subif)# no shutdown
Switch(config-subif)# exit
Switch(config-if)# exit

The following example shows how to change the management VLAN from VLAN 1 to VLAN 3 through a Telnet session. In this situation, the management command shuts down VLAN 1 and brings up VLAN 3. The Telnet session must be re-established through the new management VLAN.

Switch# configure terminal
Switch(config)# interface vlan 3
Switch(config-subif)# ip address 172.20.128.176 255.255.255.0
Switch(config-subif)# management

The following example shows how to copy the IP address and network mask information from the current management VLAN to VLAN 3 and make VLAN 3 the new management VLAN:

Switch# configure terminal
Switch(config)# interface vlan 3
Switch(config-subif)# management

You can verify the previous commands by entering the show interface and show interface vlan number command in privilege EXEC mode.

Related Commands

Command Description

management

Shuts down the current management VLAN interface and enables the new management VLAN interface.

show interface

Displays the administrative and operational status of a switching (nonrouting) port.

shutdown

Disables a port and shuts down the management VLAN.

ip address

Use the ip address interface configuration command to set an IP address for a switch. Use the no form of this command to remove an IP address or to disable IP processing.

ip address ip-address subnet-mask

no ip address ip-address subnet-mask

Syntax Description

ip-address

IP address.

subnet-mask

Mask for the associated IP subnet.

Defaults

No IP address is defined for the switch.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines

A switch can have one IP address.

If you remove the IP address through a Telnet session, your connection to the switch will be lost.

If your switch receives its IP address from a BOOTP server and you remove the switch IP address by using the no ip address command, IP processing is disabled, and the BOOTP server cannot reassign the address.

Examples

The following example shows how to configure the IP address for the switch on a subnetted network:

Switch(config)# interface vlan 1
Switch(config-if)# ip address 172.20.128.2 255.255.255.0

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

clear ip address

Deletes an IP address for a switch without disabling the IP processing.

login

Use the login line configuration command to enable password checking at login. Use the no form of this command to disable password checking and to allow connections without a password.

login [local | tacacs]

no login

Syntax Description

local

(Optional) Select local password checking. Authentication is based on the username specified with the username global configuration command.

tacacs

(Optional) Select the Terminal Access Controller Access Control System (TACACS)-style user ID and password-checking mechanism.

Defaults

No password is assigned, and you cannot access the switch through Telnet. Virtual terminals require a password. If you do not set a password for a virtual terminal, it responds to attempted connections by displaying an error message and closing the connection.

Command Modes

Line configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

If you specify the login command without the local or tacacs option, authentication is based on the password specified with the line configuration password command.

Note This command cannot be used with authentication, authorization, and accounting (AAA) and TACACS+. Use the login authentication command instead.

Examples

The following example shows how to set the password letmein on virtual terminal line 4:

Switch(config-line)# line vty 4
Switch(config-line)# password letmein
Switch(config-line)# login

The following example shows how to enable the TACACS-style user ID and password-checking mechanism:

Switch(config-line)# line 0
Switch(config-line)# password <mypassword> 
Switch(config-line)# login tacacs

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

enable password

Sets a local password to control access to various privilege levels.

password

Specifies a password on a line.

show running-config

Displays the running configuration on the switch.

username

Establishes a username-based authentication system.

login authentication

Use the login authentication line configuration command to enable authentication, authorization, and accounting (AAA) for logins. Use the no form of this command to either disable Terminal Access Controller Access Control System Plus (TACACS+) authentication for logins or to return to the default.

login authentication {default | list-name}

no login {default | list-name}

Syntax Description

default

Use the default list created with the AAA authentication login command.

list-name

Use the indicated list created with the AAA authentication login command.

Defaults

Command Modes

Line configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

To create a default list that is used if no list is specified in the login authentication command, use the default keyword followed by the methods you want used in default situations. The default method list is automatically applied to all interfaces.

Examples

The following example shows how to specify TACACS+ as the default method for user authentication during login:

Switch(config)# aaa new-model
Switch(config)# aaa authentication login default tacacs
Switch(config)# line vty 0 4
Switch(config-line)# login authentication default tacacs

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

mac-address-table aging-time

Use the mac-address-table aging-time global configuration command to set the length of time that a dynamic entry remains in the MAC address table after the entry is used or updated. Use the no form of this command to use the default aging-time interval. The aging time applies to all VLANs.

mac-address-table aging-time age

no mac-address-table aging-time

Syntax Description

age

Number from 10 to 1000000 (seconds).

Defaults

The default is 300 seconds.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines

If hosts do not transmit continuously, increase the aging time to record the dynamic entries for a longer time. This can reduce the possibility of flooding when the hosts transmit again.

Examples

The following example shows how to set the aging time to 200 seconds:

Switch(config)# mac-address-table aging-time 200

You can verify the previous command by entering the show mac-address-table command in privileged EXEC mode.

Related Commands

Command Description

clear mac-address-table

Deletes entries from the MAC address table.

mac-address-table dynamic

Adds dynamic addresses to the MAC address table.

mac-address-table secure

Adds secure addresses to the MAC address table.

port block

Blocks the flooding of unknown unicast or multicast packets to a port.

show cgmp

Displays the current state of the CGMP-learned multicast groups and routers.

show mac-address-table

Displays the MAC address table.

mac-address-table dynamic

Use the mac-address-table dynamic global configuration command to add dynamic addresses to the MAC address table. Dynamic addresses are automatically added to the address table and dropped from it when they are not in use. Use the no form of this command to remove dynamic entries from the MAC address table.

mac-address-table dynamic hw-addr interface [atm slot/port] [vlan vlan-id]

no mac-address-table dynamic hw-addr [vlan vlan-id]

Syntax Description

hw-addr

MAC address added to or removed from the table.

interface

Port to which packets destined for hw-addr are forwarded.

atm slot/port

(Optional) Add dynamic addresses to ATM module in slot 1 or 2. The port is always 0 for an ATM interface.

vlan vlan-id

(Optional) The interface and vlan parameters together specify a destination to which packets destined for hw-addr are forwarded.

The vlan keyword is optional if the port is a static-access or dynamic-access VLAN port. In this case, the VLAN assigned to the port is assumed to be that of the port associated with the MAC address.

Note When this command is executed on a dynamic-access port, queries to the VLAN Membership Policy Server (VMPS) do not occur. The VMPS cannot verify that the address is allowed or determine to which VLAN the port should be assigned. This command should only be used for testing purposes.

The vlan keyword is required for multi-VLAN and trunk ports. This keyword is required on trunk ports to specify to which VLAN the dynamic address is assigned.

The vlan-id is the ID of the VLAN to which packets destined for hw-addr are forwarded. Valid IDs are 1 to 1005; do not enter leading zeroes.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

11.2(8)SA3

The vlan keyword was added.

11.2(8)SA5

The atm keyword was added.

Usage Guidelines

If the variable vlan-id is omitted and the no form of the command is used, the MAC address is removed from all VLANs.

Examples

The following example shows how to add a MAC address on port fa1/1 to VLAN 4:

Switch(config)# mac-address-table dynamic 00c0.00a0.03fa fa1/1 vlan 4

You can verify the previous command by entering the show mac-address-table command in privileged EXEC mode.

Related Commands

Command Description

clear mac-address-table

Deletes entries from the MAC address table.

mac-address-table aging-time

Sets the length of time that a dynamic entry remains in the MAC address table after the entry is used or updated.

mac-address-table static

Adds static addresses to the MAC address table.

show mac-address-table

Displays the MAC address table.

mac-address-table secure

Use the mac-address-table secure global configuration command to add secure addresses to the MAC address table. Use the no form of this command to remove secure entries from the MAC address table.

mac-address-table secure hw-addr interface [atm slot/port] [vlan vlan-id]

no mac-address-table secure hw-addr [vlan vlan-id]

Syntax Description

hw-addr

MAC address that is added to the table.

interface

Port to which packets destined for hw-addr are forwarded.

atm slot/port

(Optional) Add secure address to the ATM module in slot 1 or 2. The port is always 0 for an ATM interface.

vlan vlan-id

(Optional) The interface and vlan parameters together specify a destination to which packets destined for hw-addr are forwarded.

The vlan keyword is optional if the port is a static-access VLAN port. In this case, the VLAN assigned to the port is assumed to be that of the port associated with the MAC address. This keyword is required for multi-VLAN and trunk ports.

The vlan-id is the ID of the VLAN to which secure entries are added. Valid IDs are 1 to 1005; do not enter leading zeroes.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

11.2(8)SA3

The vlan keyword was added.

11.2(8)SA5

The atm keyword was added.

Usage Guidelines

Secure addresses can be assigned only to one port at a time. Therefore, if a secure address table entry for the specified MAC address and VLAN already exists on another port, it is removed from that port and assigned to the specified one.

Dynamic-access ports cannot be configured with secure addresses.

Examples

The following example shows how to add a secure MAC address to VLAN 6 of port fa1/1:

Switch(config)# mac-address-table secure 00c0.00a0.03fa fa1/1 vlan 6

The following example shows how to add a secure MAC address to ATM port 2/1:

Switch(config)# mac-address-table secure 00c0.00a0.03fa atm 2/1

You can verify the previous command by entering the show mac-address-table command in privileged EXEC mode.

Related Commands

Command Description

clear mac-address-table

Deletes entries from the MAC address table.

mac-address-table aging-time

Sets the length of time that a dynamic entry remains in the MAC address table after the entry is used or updated.

mac-address-table dynamic

Adds dynamic addresses to the MAC address table.

mac-address-table static

Adds static addresses to the MAC address table.

show mac-address-table

Displays the MAC address table.

mac-address-table static

Use the mac-address-table static global configuration command to add static addresses to the MAC address table. Use the no form of this command to remove static entries from the MAC address table.

mac-address-table static hw-addr in-port out-port-list [atm slot/port] [vlan vlan-id]

no mac-address-table static hw-addr [in-port in-port] [out-port-list out-port-list] [vlan vlan-id]

Syntax Description

hw-addr

MAC address to add to the address table.

in-port

Input port from which packets received with a destination address of hw-addr are forwarded to the list of ports in the out-port-list. The in-port must belong to the same VLAN as all the ports in the out-port-list

out-port-list

List of ports to which packets received on ports in in-port are forwarded. All ports in the list must belong to the same VLAN.

atm slot/port

(Optional) Add static addresses to ATM module in slot 1 or 2. The port is always 0 for an ATM interface.

vlan vlan-id

(Optional) The interface and vlan parameters together specify a destination to which packets destined for the specified MAC address are forwarded.

The vlan keyword is optional if all the ports specified by in-port and out-port-list are static-access VLAN ports. The VLAN assigned to the ports is assumed. This keyword is required for multi-VLAN and trunk ports.

Dynamic-access ports cannot be included in static addresses as either the source (inport) or destination (outport).

The vlan keyword is required on trunk ports to specify to which VLAN the static address is assigned.

The vlan-id is the ID of the VLAN to which static address entries are forwarded. Valid IDs are 1 to 1005; do not enter leading zeroes.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

11.2(8)SA3

The vlan keyword was added.

11.2(8)SA5

The atm keyword was added.

Usage Guidelines

When a packet is received on the input port, it is forwarded to the VLAN of each port you specify for the out-port-list. Different input ports can have different output-port lists for each static address. Adding a static address already defined as one modifies the port map (vlan and out-port-list) for the input port specified.

If the variable vlan-id is omitted and the no form of the command is used, the MAC address is removed from all VLANs.

Traffic from a static address is only accepted from a port defined in the in-port variable.

Dynamic-access ports cannot be configured as the source or destination port in a static address entry.

Examples

The following example shows how to add a static address with port 1 as an input port and ports 2 and 8 of VLAN 4 as output ports:

Switch(config)# mac-address-table static c2f3.220a.12f4 fa0/1 fa0/2 fa0/8 vlan 4

You can verify the previous command by entering the show mac-address-table command in privileged EXEC mode.

Related Commands

Command Description

clear mac-address-table

Deletes entries from the MAC address table.

mac-address-table aging-time

Sets the length of time that a dynamic entry remains in the MAC address table after the entry is used or updated.

mac-address-table dynamic

Adds dynamic addresses to the MAC address table.

mac-address-table secure

Adds secure addresses to the MAC address table.

show mac-address-table

Displays the MAC address table.

management

Use the management interface configuration command to shutdown the current management VLAN interface and enable the new management VLAN interface. This command also copies the current management VLAN IP information to the new management VLAN interface if no new IP address or network mask is provided. It also copies the cluster standby group configuration to the new management VLAN.

management

Syntax Description

This command has no arguments or keywords.

Defaults

No default is defined.

Command Modes

Interface configuration

Command History

Release Modification

12.0(5)XP

This command was first introduced.

Usage Guidelines

No default management or no management command exists to return the management VLAN to its default state.

The management command is not written to the configuration file, and it is not displayed in the output of the show running-config command.

Before entering the management command, make sure the following conditions exist:

You must be able to move your network management station to a switch port assigned to the same VLAN as the new management VLAN. (Depending on your network topology, you might not need to move your network management station: for example, you have ISL routing configured on a router between two VLANs.)
Connectivity through the network must exist from the network management station to all switches involved in the management VLAN change.
The switch must already have a port assigned to the same VLAN as the management VLAN.

Use the management command to change the management VLAN on a single switch. Use the global configuration command cluster management-vlan n on the command switch to change the management VLAN on the entire cluster.

Examples

The following example shows how to shut down the current management VLAN interface and start VLAN 2 as the management VLAN:

Switch# configure terminal
Switch(config)# interface vlan 2
Switch(config-subif)# ip address 172.20.128.176 255.255.255.0
Switch(config-subif)# management
Switch(config-subif)# exit
Switch(config)#

The following example shows how to copy the IP address and network mask from the current management VLAN to VLAN 2 and make VLAN 2 the management VLAN:

Switch# configure terminal
Switch(config)# interface vlan 2
Switch(config-subif)# management
Switch(config-subif)# exit
Switch(config)#

You can verify the previous command by entering the show interface vlan number command in privileged EXEC mode.

Related Commands

Command Description

cluster management-vlan

Changes the management VLAN for the entire cluster.

interface vlan

Configures an interface type, creates a switch virtual interface to be used as the management VLAN interface, and enters interface configuration mode

show interface vlan number

Displays the administrative and operational status of a switching (nonrouting) port.

ntp access-group

Use the ntp access-group global configuration command to control access to the system Network Time Protocol (NTP) services. Use the no form of the command to remove access control to the system NTP services.

ntp access-group {query-only | serve-only | serve | peer} access-list-number

no ntp access-group {query-only | serve | peer

Syntax Description

query-only

Enable only NTP control queries. See RFC 1305 (NTP version 3).

serve-only

Enable only time requests.

serve

Enable time requests and NTP control queries, but does not enable the system to synchronize to the remote system.

peer

Enable time requests and NTP control queries; enable the system to synchronize to the remote system.

access-list-number

Number (1 to 99) of a standard IP access list

Defaults

NTP is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

The access group options are scanned in the following order from least restrictive to most restrictive:

1. peer

2. serve

3. serve-only

4. query-only

Access is granted for the first match that is found. If no access groups are specified, all access is granted to all sources. If any access groups are specified, only the specified access is granted. This facility provides minimal security for the time services of the system. If tighter security is desired, use the NTP authentication facility.

Examples

The following example shows how to configure the system to be synchronized by a peer from access list 99.

However, the system restricts access to allow only time requests from access list 42:

Switch(config)# ntp access-group peer 99
Switch(config)# ntp access-group serve-only 42

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

access-list

Differentiates one packet from another so that different treatment can be applied.

show running-config

Displays the running configuration on the switch.

ntp authenticate

Use the ntp authenticate global configuration command to enable Network Time Protocol (NTP) authentication. Use the no form of this command to disable the feature.

ntp authenticate

no ntp authenticate

Syntax Description

This command has no keywords or arguments.

Defaults

NTP authentication is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Use this command if you want authentication. If this command is specified, the system will not synchronize to a system unless it carries one of the authentication keys specified in the ntp trusted-key command.

Examples

The following example shows how to enable NTP authentication:

Switch(config)# ntp authenticate

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

ntp authentication-key

Defines an authentication key for NTP.

ntp trusted-key

Authenticates the identity of a system to which NTP will synchronize.

show running-config

Displays the running configuration on the switch.

ntp authentication-key

Use the ntp authentication-key global configuration command to define an authentication key for Network Time Protocol (NTP). Use the no form of this command to remove the authentication key for NTP.

ntp authentication-key number md5 value

no ntp authentication-key number

Syntax Description

number

Key number (1 to 4294967295).

md5

Use MD5 authentication.

value

Key value (an arbitrary string of up to eight characters, with the exception of control or escape characters).

Defaults

No authentication key is defined.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Use this command to define authentication keys for use with other NTP commands for greater security.

Examples

The following example shows how to set authentication key 10 to aNiceKey:

Switch(config)# ntp authentication-key 10 md5 aNiceKey

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Note When this command is written to nonvolatile RAM (NVRAM), the key is encrypted so that it is not displayed when the configuration is viewed.

Related Commands

Command Description

ntp authentication

Enables NTP authentication.

ntp peer

Configures the switch system clock to synchronize a peer or to be synchronized by a peer.

ntp server

Allows the switch system clock to be synchronized by a time server.

ntp trusted-key

Authenticates the identity of a system to which NTP will synchronize.

show running-config

Displays the running configuration on the switch.

ntp broadcast client

Use the ntp broadcast client interface configuration command to allow the system to receive Network Time Protocol (NTP) broadcast packets on an interface. Use the no form of the command to disable this capability.

ntp broadcast client

no ntp broadcast [client]

Syntax Description

This command has no arguments or keywords.

Defaults

Broadcast client mode is disabled.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Use this command to allow the system to listen to broadcast packets on an interface-by-interface basis. You must configure this command on the management VLAN interface. By default, the management VLAN is VLAN 1, but you can configure a different VLAN as the management VLAN.

Examples

The following example shows how to synchronize the router to NTP packets that are broadcast on interface VLAN1:

Switch(config-if)# interface vlan1
Switch(config-if)# ntp broadcast client

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

ntp broadcastdelay

Sets the estimated round-trip delay between the IOS software and an NTP broadcast server.

show running-config

Displays the running configuration on the switch.

ntp broadcastdelay

Use the ntp broadcastdelay global configuration command to set the estimated round-trip delay between the IOS software and a Network Time Protocol (NTP) broadcast server. Use the no form of this command to revert to the default value.

ntp broadcastdelay microseconds

no ntp broadcastdelay

Syntax Description

microseconds

Estimated round-trip time (in microseconds) for NTP broadcasts. The range is from 1 to 999999.

Defaults

The default is 3000 microseconds.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Use this command when the switch is configured as a broadcast client and the round-trip delay on the network is other than 3000 microseconds.

Examples

The following example shows how to configure the estimated round-trip delay between the switch and the broadcast client to 5000 microseconds:

Switch(config)# ntp broadcastdelay 5000

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

ntp broadcast client

Allows the system to receive NTP broadcast packets on an interface.

show running-config

Displays the running configuration on the switch.

ntp broadcast destination

Use the ntp broadcast destination interface configuration command to configure a Network Time Protocol (NTP) server or peer to restrict the broadcast of NTP frames to the IP address of a designated client or a peer. Use the no form of the command to return the setting to its default.

ntp broadcast destination IP-address

no ntp broadcast destination

Syntax Description

IP-address

IP address or host name of a designated client or a peer.

Defaults

No IP address or host name is assigned.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

You must configure this command on the management VLAN interface. By default, the management VLAN is VLAN 1, but you can configure a different VLAN as the management VLAN.

Related Commands

Command Description

ntp broadcast client

Allows the system to receive NTP broadcast packets on an interface.

ntp broadcastdelay

Sets the estimated round-trip delay between the IOS software and an NTP broadcast server.

ntp broadcast key

Use the ntp broadcast key interface configuration command to configure a Network Time Protocol (NTP) server or peer to broadcast NTP frames with the authentication key embedded into the NTP packet. Use the no form of the command to return the setting to its default.

ntp broadcast key number

no ntp broadcast key

Syntax Description

number

The NTP authentication key that is embedded in the NTP packet.
The range is from 0 to 4294967295.

Defaults

No NTP broadcast key is defined.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

You must configure this command on the management VLAN interface. By default, the management VLAN is VLAN 1, but you can configure a different VLAN as the management VLAN.

ntp broadcast version

Use the ntp broadcast interface configuration command to specify that a specific interface should send Network Time Protocol (NTP) broadcast packets. Use the no form of the command to disable this capability.

ntp broadcast version number

no ntp broadcast

Syntax Description

number

Number from 1 to 3.

Defaults

Version 3 is the default.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

If you are using version 2 and the NTP synchronization does not occur, use NTP version 2.

You must configure this command on the management VLAN interface. By default, the management VLAN is VLAN 1, but you can configure a different VLAN as the management VLAN.

Examples

The following example shows how to configure interface VLAN 1 to send NTP version 2 packets:

Switch(config-if)# interface vlan1
Switch(config-if)# ntp broadcast version 2

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

ntp clock-period

Do not enter this command; it is documented for informational purposes only. The system automatically generates this command as the Network Time Protocol (NTP) determines the clock error and compensates.

As the NTP compensates for the error in the system clock, it keeps track of the correction factor for this error. The system automatically saves this value into the system configuration using the ntp clock-period global configuration command. The system uses the no form of this command to revert to the default.

ntp clock-period value

no ntp clock-period

Syntax Description

value

Amount to add to the system clock for each clock hardware tick (in units of 2 to 32 seconds).

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

If a write memory command is entered to save the configuration to nonvolatile RAM (NVRAM), this command is automatically added to the configuration. It is a good idea to perform this task after NTP has been running for a week or so; NTP synchronizes more quickly if the system is restarted.

ntp disable

Use the ntp disable interface configuration command to prevent an interface from receiving Network Time Protocol (NTP) packets. To enable receipt of NTP packets on an interface, use the no form of the command.

ntp disable

no ntp disable

Syntax Description

This command has no arguments or keywords.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

You must configure this command on the management VLAN interface. By default, the management VLAN is VLAN 1, but you can configure a different VLAN as the management VLAN.

The preferred command to disable NTP is no ntp.

Examples

The following example shows how to prevent interface VLAN 1 from receiving NTP packets:

Switch(config-if)# interface vlan1
Switch(config-if)# ntp disable

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

ntp max-associations

Use the ntp max-associations global configuration command to set the maximum number of Network Time Protocol (NTP) associations that are allowed on a server. Use the no form of this command to disable this feature.

ntp max-associations [number]

no ntp max-associations

Syntax Description

number

(Optional) Specify the number of NTP associations. The range is from
0 to 4294967295.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

This command provides a simple method to control the number of peers that can use the switch to synchronize to it through NTP.

After you enable a switch as an NTP server, use this command to set the maximum number of associations that are allowed on a server.

Examples

The following example shows how to set the maximum number of NTP associations to 44:

Switch(config)# ntp max-associations 44

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

ntp peer

Use the ntp peer global configuration command to configure the switch system clock to synchronize a peer or to be synchronized by a peer. Use the no form of the command to disable this capability.

ntp peer ip-address [version number] [key keyid] [source interface] [prefer]

no ntp peer ip-address

Syntax Description

ip-address

IP address of the peer providing, or being provided, the clock synchronization.

version number

(Optional) Define the Network Time Protocol (NTP) version number as version 1, 2, or 3.

key keyid

(Optional) Define the authentication key, which is used when sending packets to this peer. The range is from 0 to 4294967295.

source interface

(Optional) Authentication key to use when sending packets to this peer. Also includes the name of the interface from which to pick the IP source address.

prefer

(Optional) Make this peer the preferred peer that provides synchronization.

Defaults

No IP address is defined.

NTP version 3 is the default.

No NTP authentication key is defined.

No source interface is defined.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Using the prefer keyword will reduce switching between peers.

If you are using the default NTP version of 3 and NTP synchronization does not occur, try using NTP version 2. Many NTP servers on the Internet run version 2.

Examples

The following example shows how to configure the router to allow its system clock to be synchronized with the clock of the peer (or vice versa) at IP address 131.108.22.33 using NTP version 2. The source IP address will be the address of Ethernet 0.

Switch(config)# ntp peer 131.108.22.33 version 2 source Ethernet 0

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

ntp authentication-key

Defines an authentication key for NTP.

ntp server

Allows the switch system clock to be synchronized by a time server.

ntp source

Uses a particular source address in NTP packets.

show running-config

Displays the running configuration on the switch.

ntp server

Use the ntp server global configuration command to allow the switch system clock to be synchronized by a time server. Use the no form of the command to disable this capability.

ntp server ip-address [version number] [key keyid] [source interface] [prefer]

no ntp server ip-address

Syntax Description

ip-address

IP address of the time server providing the clock synchronization.

version number

(Optional) Define the Network Time Protocol (NTP) version number (1 to 3).

key keyid

(Optional) Define the authentication key. Authentication key to use when sending packets to this peer. The range is from 0 to 4294967295.

source interface

(Optional) Identify the interface from which to pick the IP source address.

prefer

(Optional) Make this server the preferred server that provides synchronization.

Defaults

No IP address is defined.

NTP version 3 is the default.

No NTP authentication key is defined.

No source interface is defined.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Use this command if you want to allow this machine to synchronize with the specified server. The server will not synchronize to this machine.

Using the prefer keyword will reduce switching between servers.

If you are using the default NTP version of 3 and NTP synchronization does not occur, try using NTP version 2. Many NTP servers on the Internet run version 2.

Examples

The following example shows how to configure the router to allow its system clock to be synchronized with the clock of the peer at IP address 128.108.22.44 using NTP version 2:

Switch(config)# ntp server 128.108.22.44 version 2

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

ntp source

Use the ntp source global configuration command to use a particular source address in Network Time Protocol (NTP) packets. Use the no form of this command to remove the specified source address.

ntp source interface

no ntp source

Syntax Description

interface

Any valid system interface name.

Defaults

No source address is defined.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Use this command when you want to use a particular source IP address for all NTP packets. The address is taken from the specified interface. This command is useful if the address on an interface cannot be used as the destination for reply packets. If the source keyword is present on an ntp server or ntp peer command, that value overrides the global value.

Examples

The following example shows how to configure the router to use the IP address of VLAN1 as the source address of all outgoing NTP packets:

Switch(config)# ntp source vlan1

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

ntp peer

Configures the switch system clock to synchronize a peer or to be synchronized by a peer.

ntp server

Allows the switch system clock to be synchronized by a time server.

show running-config

Displays the running configuration on the switch.

ntp trusted-key

Use the ntp trusted-key global configuration command if you want to authenticate the identity of a system to which the Network Time Protocol (NTP) will synchronize. Use the no form of this command to disable authentication of the identity of the system.

ntp trusted-key key-number

no ntp trusted-key key-number

Syntax Description

key-number

Authentication key to be used for time authentication. The range is from
1 to 4294967295.

Defaults

No key number is defined.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

If authentication is enabled, use this command to define one or more key numbers that a peer NTP system must provide in its NTP packets in order for this system to synchronize to it. The key numbers must correspond to the keys defined with the ntp authentication-key command. This provides protection against accidentally synchronizing the system to a system that is not allowed because the other system must know the correct authentication key.

Examples

The following example shows how to configure the system to synchronize only to systems providing authentication key 42 in its NTP packets:

Switch(config)# ntp authenticate
Switch(config)# ntp authentication-key 42 md5 aNiceKey
Switch(config)# ntp trusted-key 42

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

ntp authenticate

Enables NTP authentication.

ntp authentication-key

Defines an authentication key for NTP.

show running-config

Displays the running configuration on the switch.

port block

Use the port block interface configuration command to block the flooding of unknown unicast or multicast packets to a port. Use the no form of this command to resume normal forwarding.

port block {unicast | multicast}

no port block {unicast | multicast}

Syntax Description

unicast

Packets with unknown unicast addresses are not forwarded to this port

multicast

Packets with unknown multicast addresses are not forwarded to this port.

Defaults

Flood unknown unicast and multicast packets to all ports.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines

The port block command cannot be entered for a network port.

If a trunk port is not a network port, the unicast keyword applies. The multicast keyword is supported on trunk ports. Both port block features affect all the VLANs associated with the trunk port.

Examples

The following example shows how to block the forwarding of multicast and unicast packets to a port:

Switch(config-if)# port block unicast
Switch(config-if)# port block multicast

You can verify the previous commands by entering the show port block command in privileged EXEC mode.

Related Commands

Command Description

show port block

Displays the blocking of unicast or multicast flooding to a port.

port group

Use the port group interface configuration command to assign a port to a Fast EtherChannel or Gigabit EtherChannel port group. Up to 12 port groups can be created on a switch. Any number of ports can belong to a destination-based port group. Up to eight ports can belong to a source-based port group. Use the no form of this command to remove a port from a port group.

port group group-number [distribution {source | destination}]

no port group

Syntax Description

group-number

Port group number to which the port belongs. The range is
from 1 to 12.

distribution {source | destination}

(Optional) Forwarding method for the port group.

source---Set the port to forward traffic to a port group based on the packet source address. This is the default forwarding method

destination---Set the port to forward traffic to a port group based on the packet destination address.

Defaults

Port does not belong to a port group.

The default forwarding method is source.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

An ATM port is the only port that cannot belong to a port group. For all other ports, the following restrictions apply:

Do not group Fast Ethernet and gigabit ports together.
No port group member can be configured for Switched Port Analyzer (SPAN) port monitoring.
No port group member can be enabled for port security.
You can create up to 12 port groups of all source-based, all destination-based, or a combination of source-based and destination-based port groups. A source-based port group can have up to eight ports in its group. A destination-based port group can contain an unlimited number of ports in its group. You cannot mix source-based and destination-based ports in the same group.
Port group members must belong to the same set of VLANs and must be all static-access, all multi-VLAN, or all trunk ports.
Dynamic-access ports cannot be grouped with any other port, not even with other dynamic-access ports.

When a group is first formed, the switch automatically sets the following parameters to be the same on all ports:

VLAN membership of ports in the group
VLAN mode (static, multi, trunk) of ports in the group
Encapsulation method of the trunk
Native VLAN configuration if the trunk uses IEEE 802.1Q
Allowed VLAN list configuration of the trunk port
Spanning Tree Protocol (STP) Port Fast option
STP port priority
STP path cost
Network port configuration for source-based port group
Protected port

Configuration of the first port added to the group is used when setting the above parameters for other ports in the group. After a group is formed, changing any parameter in the above list changes the parameter on all other ports.

Use the distribution keyword to customize the port group to your particular environment. The forwarding method you choose depends on how your network is configured. However, source-based forwarding works best for most network configurations.

This command is not supported on the ATM modules.

Examples

The following example shows how to add a port to a port group using the default source-based forwarding:

Switch(config-if)# port group 1

The following example shows how to add a port to a group using destination-based forwarding:

Switch(config-if)# port group 2 distribution destination

You can verify the previous commands by entering the show port group command in privileged EXEC mode.

Related Commands

Command Description

show port group

Displays the ports that belong to a port group.

port monitor

Use the port monitor interface configuration command to enable Switch Port Analyzer (SPAN) port monitoring on a port. Use the no form of this command to return the port to its default value.

port monitor [interface | vlan vlan-id]

no port monitor [interface | vlan vlan-id]

Syntax Description

interface

(Optional) Module type, slot, and port number for the SPAN to be enabled. The interface specified is the port to be monitored.

vlan vlan-id

(Optional) ID of the VLAN to be monitored. Valid IDs are from 1 to 1000; do not enter leading zeroes. A monitor port must be a member of the same VLAN as the port monitored.

Defaults

Port does not monitor any other ports.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

11.2(8)SA3

The vlan keyword was added.

Usage Guidelines

Enabling port monitoring without specifying a port causes all other ports in the same VLAN to be monitored.

Entering the port monitor vlan 1 command causes monitoring of all traffic to and from the IP address configured on VLAN 1.

ATM ports are the only ports that cannot be monitor ports. However, you can monitor ATM ports. The following restrictions apply for ports that have port-monitoring capability:

A monitor port cannot be in a Fast EtherChannel or Gigabit EtherChannel port group.
A monitor port cannot be enabled for port security.
A monitor port cannot be a multi-VLAN port.
A monitor port must be a member of the same VLAN as the port monitored. VLAN membership changes are disallowed on monitor ports and ports being monitored.
A monitor port cannot be a dynamic-access port or a trunk port. However, a static-access port can monitor a VLAN on a trunk, a multi-VLAN, or a dynamic-access port. The VLAN monitored is the one associated with the static-access port.
Port monitoring does not work if both the monitor and monitored ports are protected ports.

Examples

The following example shows how to enable port monitoring on port fa0/2:

Switch(config-if)# port monitor fa0/2

You can verify the previous command by entering the show port monitor command in privileged EXEC mode.

Related Commands

Command Description

show port monitor

Displays the ports for which SPAN port monitoring is enabled.

port network

Use the port network interface configuration command to define a port as the switch network port. All traffic with unknown unicast addresses is forwarded to the network port on the same VLAN. Use the no form of this command to return the port to the default value.

port network

no port network

Syntax Description

This command has no arguments or keywords.

Defaults

No network port is defined.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

The following restrictions apply to network ports:

A network port can be a static-access port, a multi-VLAN port, a port group, or a trunk port. Both the multi-VLAN port and the trunk port become the network port for all the VLANs associated with that port.
A network port cannot be an ATM, a secure, a monitor, a protected, or a dynamic-access port. You can assign a dynamic-access port to a VLAN in which another port is the network port.
Each VLAN can have one network port.
A network port cannot be in a destination-based port group.
A network port cannot be on an ATM module.
A network port cannot be a protected port.

Examples

The following example shows how to set a port as a network port:

Switch(config-if)# port network

You can verify the previous command by entering the show port network command in privileged EXEC mode.

Related Commands

Command Description

show port network

Displays the network port defined for the switch or VLAN.

port protected

Use the port protected interface configuration command to isolate unicast, multicast, and broadcast traffic at Layer 2 from other protected ports on the same switch. Use the no form of the command to disable the protected port.

port protected

no port protected

Syntax Description

This command has no keywords or arguments.

Defaults

No protected port is defined.

A protected port does not forward any unicast, multicast, or broadcast traffic to any other protected port.

A protected port continues to forward unicast, multicast, and broadcast traffic to unprotected ports and vice versa.

Command Modes

Interface configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

The port protection feature is local to the switch; communication between protected ports on the same switch is possible only through a Layer 3 device. To prevent communication between protected ports on different switches, you must configure the protected ports for unique VLANs on each switch and configure a trunk link between the switches.

A protected port cannot be a network port.

Port monitoring does not work if both the monitor and monitored ports are protected ports.

A protected port is different from a secure port.

Examples

The following example shows how to enable a protected port on interface fa0/3:

Switch(config)# interface fa0/3
Switch(config-if)# port protected

You can verify the previous command by entering the show port protected command in privileged EXEC mode.

Related Commands

Command Description

show port protected

Displays the ports that are in port-protected mode.

port security

Use the port security interface configuration command to enable port security on a port and restrict the use of the port to a user-defined group of stations. Use the no form of this command to return the port to its default value.

port security [action {shutdown | trap} | max-mac-count addresses]

no port security

Syntax Description

action {shutdown | trap}

(Optional) Action to take when an address violation occurs on this port.

shutdown---Disable the port when a security violation occurs.

trap---Generate an SNMP trap when a security violation occurs

max-mac-count addresses

(Optional) The maximum number of secure addresses that this port can support. The range is from 1 to 132.

Defaults

Port security is disabled.

When enabled, the default action is to generate an SNMP trap.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines

If you specify trap, use the snmp-server host command to configure the SNMP trap host to receive traps.

The following restrictions apply to secure ports:

A secure port cannot belong to a Fast EtherChannel or Gigabit EtherChannel port group.
A secure port cannot have Switched Port Analyzer (SPAN) port monitoring enabled on it.
A secure port cannot be a multi-VLAN port.
A secure port cannot be a network port.
A secure port cannot be an ATM port.
A secure port cannot be a dynamic-access port or a trunk port.

Examples

The following example shows how to enable port security and what action the port takes in case of an address violation (shutdown).

Switch(config-if)# port security action shutdown

The following example shows how to set the maximum number of addresses that the port can learn to 8.

Switch(config-if)# port security max-mac-count 8

You can verify the previous commands by entering the show port security command in privileged EXEC mode.

Related Commands

Command Description

show port security

Displays the port security settings defined for the port.

port storm-control

Use the port storm-control interface configuration command to enable broadcast, multicast, or unicast storm control on a port. Use the no form of this command to disable storm control or one of the storm-control parameters on the port.

port storm-control {broadcast | multicast | unicast} {{action {filter | shutdown} | threshold {rising rising-number falling falling-number} | trap}}

no port storm-control {broadcast | multicast | unicast}

Syntax Description

{broadcast | multicast | unicast}

Determine the type of packet-storm suppression.

broadcast---Enable broadcast storm control on the port.

multicast---Enable multicast storm control on the port.

unicast---Enable unicast storm control on the port.

{action {filter | shutdown}

(Optional) Determines the type of action to perform.

filter---Filter traffic during a storm.

shutdown---Disable the port during a storm.

threshold {rising rising-number falling falling-number}

Defines the rising and falling thresholds

rising rising-number---Block the flooding of storm packets when the value specified for rising-number is reached. The rising-number is 0 to 4294967295 packets per second.

falling falling-number---Restart the normal transmission of broadcast packets when the value specified for falling-number is reached. The falling-number is 0 to 4294967295 packets per second.

trap

(Optional) Generate an SNMP trap when the traffic on the port crosses the rising or falling threshold. Traps are generated only for broadcast traffic and not for unicast or multicast traffic.

Defaults

Broadcast, multicast, and unicast storm control are disabled.

The rising thresholds are 500 broadcast packets per second, 2500 multicast packets per second, and 5000 unicast packets per second.

The falling thresholds are 250 broadcast packets per second, 1200 multicast packets per second, and 2500 unicast packets per second.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

12.0(5)XU

The multicast, unicast, action, and shutdown keywords were added.

Usage Guidelines

Do not set the rising and falling thresholds to the same value.

Examples

The following example shows how to enable broadcast storm control on a port. In this example, transmission is inhibited when the number of broadcast packets arriving on the port reaches 1000 and is restarted when the number drops to 200.

Switch(config-if)# port storm-control broadcast threshold rising 1000 falling 200

You can verify the previous command by entering the show port storm-control command in privileged EXEC mode.

Related Commands

Command Description

show port storm-control

Displays the packet-storm control information.

power inline

Use the power inline interface configuration command to determine how inline power is applied to the device on the specified Fast Ethernet port of the 3524-PWR-XL switch. Use the no form of this command to return the setting to its default.

power inline {auto | never}

no power inline

Syntax Description

auto

Automatically detect and power inline devices.

never

Never apply inline power.

Defaults

Power is applied when a telephone is detected on the port (auto).

Command Modes

Interface configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Examples

The following example shows how to always apply power to the port:

Switch(config-if)# power inline auto

You can verify the previous command by entering the show power inline command in privileged EXEC mode.

Related Commands

Command Description

show power inline

Displays the power status for the specified port or for all ports.

switchport priority extend

Determines how the telephone connected to the specified port handles priority traffic received on its incoming port.

switchport voice vlan

Configures the voice VLAN on the port.

rcommand

Use the rcommand user EXEC command to start a Telnet session and to execute commands on a member switch from the command switch. To end the session, enter the exit command.

rcommand {n | commander | mac-address hw-addr}

Syntax Description

n

Provide the number that identifies a cluster member. The range is from 0 to 15.

commander

Provide access to the command switch from a member switch.

mac-address hw-addr

MAC address of the member switch.

Command Modes

User EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

If the switch is the command switch but the member switch n does not exist, an error message appears. To obtain the switch number, enter the EXEC mode show cluster members command on the command switch.

You can use this command to access a member switch from the command-switch prompt or to access a command switch from the member-switch prompt.

For 2900 and 3500 XL switches, the Telnet session accesses the member-switch command-line interface (CLI) at the same privilege level as on the command switch. For example, if you execute this command at user level on the cluster command switch, the member switch is accessed at user level. If you use this command on the command switch at privileged level, the command accesses the remote device at privileged level. If you use an intermediate enable-level lower than privileged, access to the member switch is at user level.

For Catalyst 1900 and 2820 switches running standard edition software, the Telnet session accesses the menu console (the menu-driven interface) if the command switch is at privilege level 15. If the command switch is at privilege level 1, you are prompted for the password before being able to access the menu console. Command switch privilege levels map to the member switches running standard edition software as follows:

If the command switch privilege level is from 1 to 14, the member switch is accessed at privilege level 1.
If the command switch privilege level is 15, the member switch is accessed at privilege level 15.

The Catalyst 1900 and 2820 CLI is available only on switches running Enterprise Edition Software.

This command will not work if the vty lines of the command switch have access-class configurations.

You are not prompted for a password because the member switches inherited the password of the command switch when they joined the cluster.

Examples

The following example shows how to start a session with member 3. All subsequent commands are directed to member 3 until you enter the exit command or close the session.

Switch# rcommand 3
Switch-3# show version
Cisco Internet Operating System Software ...
...
Switch-3# exit
Switch#

Related Commands

Command Description

show cluster members

Displays information about the cluster members.

reset

Use the reset VLAN database command to abandon the proposed VLAN database and remain in VLAN database mode. This command resets the proposed database to the currently implemented VLAN database on the switch.

reset

Syntax Description

This command has no arguments or keywords.

Defaults

No default is defined.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

The following example shows how to abandon the proposed VLAN database and reset to the current VLAN database:

Switch(vlan)# reset
Switch(vlan)#

You can verify the previous command by entering the show changes and show proposed commands in VLAN database mode.

Related Commands

Command Description

abort

Abandons the proposed new VLAN database, exits VLAN database mode, and returns to privileged EXEC mode.

apply

Implements the proposed new VLAN database, increments the database configuration revision number, propagates it throughout the administrative domain, and remains in VLAN database mode.

exit

Implements the proposed new VLAN database, increments the database configuration number, propagates it throughout the administrative domain, and returns to privileged EXEC mode.

show changes

Displays the differences between the VLAN database currently on the switch and the proposed VLAN database.

show proposed

Displays the proposed VLAN database or a selected VLAN from it.

shutdown vlan

Shuts down (suspends) local traffic on the specified VLAN.

vlan database

Enters VLAN database mode from the command-line interface (CLI).

session

Use the session privileged EXEC command to log into the ATM module operating system and to start a command-line interface (CLI) session. Enter the exit command, or press Ctrl-G to return to the switch command-line interface.

session number

Syntax Description

number

Slot number (1 or 2).

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA5

This command was first introduced.

Examples

The following example shows how to log into the ATM module number 1:

Switch# session 1

Related Commands

Command Description

exit

Exits the session with the ATM module and returns you to the CLI.

show cgmp

Use the show cgmp privileged EXEC command to display the current state of the Cisco Group Management Protocol (CGMP)-learned multicast groups and routers.

show cgmp [state | holdtime | [vlan vlan-id] | [group [address] | router [address]]]

Syntax Description

state

(Optional) Display whether CGMP is enabled or not, whether Fast Leave is enabled or not, and the router port timeout value.

holdtime

(Optional) Display the router port timeout value in seconds.

vlan vlan-id

(Optional) Limit the display to the specified VLAN. Valid IDs are from 1 to 1001; do not enter leading zeroes.

group address

(Optional) Display all known multicast groups and the destination ports. Limited to given VLAN if vlan keyword is entered; limited to a specific group if the address variable is entered. The address is the MAC address of the group.

router address

(Optional) Display all routers, their ports, and expiration times. Limited to given VLAN if the vlan keyword entered; limited to a specific router if the address variable is entered. The address is the MAC address of the router.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

This command displays CGMP information about known routers and groups, as well as whether CGMP is enabled, whether Fast Leave is enabled, and the current value of the router timeout. If show cgmp is entered with no arguments, all information is displayed.

Examples

The following is sample output from the show cgmp command.

Switch# show cgmp
 
CGMP is running.
CGMP Fast Leave is not running.
CGMP Allow reserved address to join GDA.
Default router timeout is 300 sec.
 
 
vLAN     IGMP MAC Address   Interfaces
------  -----------------   -----------
    1    0100.5e01.0203      Fa0/8
    1    0100.5e00.0128      Fa0/8
 
 
vLAN     IGMP Router        Expire   Interface
------  -----------------  --------  ----------
    1    0060.5cf3.d1b3     197 sec   Fa0/8

Related Commands

Command Description

cgmp

Enables CGMP. Also enables and disables the Fast Leave parameter and sets the router port aging time.

clear cgmp

Deletes information that was learned by the switch using CGMP.

show changes

Use the show changes VLAN database command to display the differences between the VLAN database currently on the switch and the proposed VLAN database. You can also display the differences between the two for a selected VLAN.

show changes [vlan-id]

Syntax Description

vlan-id

(Optional) ID of the VLAN in the current or proposed database. If this variable is omitted, all the differences between the two VLAN databases are displayed, including the pruning state and Version 2 mode. Valid IDs are from 1 to 1005; do not enter leading zeroes.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

The following is sample output from the show changes command. It displays the differences between the current and proposed databases.

Switch(vlan)# show changes
 
DELETED:
  VLAN ISL Id: 4
    Name: VLAN0004
    Media Type: Ethernet
    VLAN 802.10 Id: 100004
    State: Operational
    MTU: 1500
 
DELETED:
  VLAN ISL Id: 6
    Name: VLAN0006
    Media Type: Ethernet
    VLAN 802.10 Id: 100006
    State: Operational
    MTU: 1500
 
MODIFIED:
  VLAN ISL Id: 7
    Current State: Operational
    Modified State: Suspended

The following is sample output from the show changes 7 command. It displays the differences between VLAN 7 in the current database and the proposed database.

Switch(vlan)# show changes 7
 
MODIFIED:
  VLAN ISL Id: 7
    Current State: Operational
    Modified State: Suspended

Related Commands

Command Description

show current

Displays the current VLAN database on the switch or a selected VLAN from it.

show proposed

Displays the proposed VLAN database or a selected VLAN from it.

show cluster

Use the show cluster user EXEC command to display the cluster status and a summary of the cluster to which the switch belongs. This command can be entered on command and member switches.

show cluster

Syntax Description

This command has no arguments or keywords.

Command Modes

User EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

If the switch is not a command switch or a member switch, the command displays an empty line at the prompt.

On a member switch, this command displays the identity of the command switch, the switch member number, and the state of its connectivity with the command switch.

On a command switch, this command displays the cluster name, and the total number of members. It also shows the cluster status and time since the status changed. If redundancy is enabled, it displays the primary and secondary command-switch information.

If you enter this command on a switch that is not a cluster member, the error message Not a management cluster member is displayed.

Examples

The following is sample output when this command is executed on the active command switch:

Switch# show cluster
Command switch for cluster "Ajang"
        Total number of members:        7
        Status:                         1 members are unreachable
        Time since last status change:  0 days, 0 hours, 2 minutes
        Redundancy:                     Enabled
                Standby command switch: Member 1
                Standby Group:          Ajang_standby
                Standby Group Number:   110
        Heartbeat interval:             8
        Heartbeat hold-time:            80
        Extended discovery hop count:   3

The following is sample output when this command is executed on a member switch:

Switch1# show cluster
Member switch for cluster "hapuna"
        Member number:                  3
        Management IP address:          192.192.192.192
        Command switch mac address:     0000.0c07.ac14
        Heartbeat interval:             8
        Heartbeat hold-time:            80

The following is sample output when this command is executed on a member switch that is configured as the standby command switch:

Switch# show cluster
Member switch for cluster "hapuna"
        Member number:                  3 (Standby command switch)
        Management IP address:          192.192.192.192
        Command switch mac address:     0000.0c07.ac14
        Heartbeat interval:             8
        Heartbeat hold-time:            80

The following is sample output when this command is executed on the command switch that is separated from member 1:

Tahiti-24> show cluster
Command switch for cluster "Ajang"
        Total number of members:        7
        Status:                         1 members are unreachable
        Time since last status change:  0 days, 0 hours, 5 minutes
        Redundancy:                     Disabled
        Heartbeat interval:             8
        Heartbeat hold-time:            80
        Extended discovery hop count:   3

The following is sample output when this command is executed on a member switch that is separated from the command switch:

Tahiti-12> show cluster
Member switch for cluster "hapuna"
        Member number:                  <UNKNOWN>
        Management IP address:          192.192.192.192
        Command switch mac address:     0000.0c07.ac14
        Heartbeat interval:             8
        Heartbeat hold-time:            80

Related Commands

Command Description

cluster enable

Enables a command-capable switch as the cluster command switch, assigns a cluster name, and optionally assigns a member number to it.

show cluster candidates

Displays a list of candidate switches.

show cluster members

Displays information about the cluster members.

show cluster candidates

Use the show cluster candidates user EXEC command on the command switch to display a list of candidate switches.

show cluster candidates [mac-address H.H.H. | detail]

Syntax Description

mac-address H.H.H.

(Optional) MAC address of the cluster candidate.

detail

(Optional) Display detailed information for all candidates.

Command Modes

User EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

12.0(5)XU

The detail keyword was added.

Usage Guidelines

You should enter this command only on a command switch.

If the switch is not a command switch, the command displays an empty line at the prompt.

The SN in the display means "switch member number." If E is displayed in the SN column, it means that the switch is discovered through extended discovery. The hop count is the number of devices the candidate is from the command switch.

Examples

The following is sample output from the show cluster candidates command.

Switch# show cluster candidates

                                                             |---Upstream---|
MAC Address    Name         Device Type      PortIf  FEC Hops SN PortIf  FEC
00d0.7961.c4c0 Tahiti-12    WS-C3512-XL      Fa0/3        1   0  Fa0/13      
00d0.bbf5.e900 ldf-dist-128 WS-C3524-XL      Fa0/7        1   0  Fa0/24      
00e0.1e7e.be80 1900_Switch  1900             3        0   1   0  Fa0/11      
00e0.1e9f.7a00 Surfers-24   WS-C2924-XL      Fa0/5        1   0  Fa0/3       
00e0.1e9f.8c00 Surfers-12-2 WS-C2912-XL      Fa0/4        1   0  Fa0/7       
00e0.1e9f.8c40 Surfers-12-1 WS-C2912-XL      Fa0/1        1   0  Fa0/9

0050.2e4a.9fb0 murali-132 WS-C3508-XL E

0050.354e.7cd0 murali-134 WS-C2924-XL E

The following is sample output from the show cluster candidates command that uses the MAC address of a member switch directly connected to the command switch:

Switch# show cluster candidates mac-address 00d0.7961.c4c0
Device 'Tahiti-12' with mac address number 00d0.7961.c4c0
        Device type:            cisco WS-C3512-XL
        Upstream MAC address:   00d0.796d.2f00 (Cluster Member 0)
        Local port:             Fa0/3   FEC number: 
        Upstream port:          Fa0/13  FEC Number: 
        Hops from cluster edge: 1
        Hops from command device: 1

The following is sample output from the show cluster candidates command that uses the MAC address of a member switch three hops from the cluster edge:

Switch# show cluster candidates mac-address 0010.7bb6.1cc0
Device 'Ventura' with mac address number 0010.7bb6.1cc0
        Device type:            cisco WS-C2912MF-XL
        Upstream MAC address:   0010.7bb6.1cd4
        Local port:             Fa2/1   FEC number: 
        Upstream port:          Fa0/24  FEC Number: 
        Hops from cluster edge: 3
        Hops from command device: -

The following is sample output from the show cluster candidates detail command:

Switch# show cluster candidates detail
Device 'Tahiti-12' with mac address number 00d0.7961.c4c0
        Device type:            cisco WS-C3512-XL
        Upstream MAC address:   00d0.796d.2f00 (Cluster Member 1)
        Local port:             Fa0/3   FEC number: 
        Upstream port:          Fa0/13  FEC Number: 
        Hops from cluster edge: 1
        Hops from command device: 2
	Device '1900_Switch' with mac address number 00e0.1e7e.be80
        Device type:            cisco 1900
        Upstream MAC address:   00d0.796d.2f00 (Cluster Member 2)
        Local port:             3       FEC number: 0
        Upstream port:          Fa0/11  FEC Number: 
        Hops from cluster edge: 1
        Hops from command device: 2
Device 'Surfers-24' with mac address number 00e0.1e9f.7a00
        Device type:            cisco WS-C2924-XL
        Upstream MAC address:   00d0.796d.2f00 (Cluster Member 3)
        Local port:             Fa0/5   FEC number: 
        Upstream port:          Fa0/3   FEC Number: 
        Hops from cluster edge: 1
        Hops from command device: 2

Related Commands

Command Description

show cluster

Displays the cluster status and a summary of the cluster to which the switch belongs.

show cluster members

Displays information about the cluster members.

show cluster members

Use the show cluster members user EXEC command on the command switch to display information about the cluster members.

show cluster members [n | detail]

Syntax Description

n

(Optional) Number that identifies a cluster member. The range is from 0 to 15.

detail

(Optional) Display detailed information for all cluster members.

Command Modes

User EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

12.0(5)XU

The detail keyword was added.

Usage Guidelines

You should enter this command only on a command switch.

If the cluster has no members, this command displays an empty line at the prompt.

Examples

The following is sample output from the show cluster members command. The SN in the display means "switch number."

Switch# show cluster members
 
                                                |---Upstream---|
SN MAC Address    Name         PortIf FEC Hops   SN PortIf  FEC  State
0  00d0.796d.2f00 Tahiti-24                0                     Up (Cmdr)
1  00d0.7960.66c0                          255                   Down
2  00e0.1e9f.8c00 Surfers-12-2 Fa0/4       1     0  Fa0/7        Up (Standby)
3  00e0.1e9f.7a00 Surfers-24   Fa0/5       1     0  Fa0/3        Up
4  00d0.bbf5.e900 ldf-dist-128 Fa0/7       1     0  Fa0/24       Up
5  00d0.7961.c4c0 Tahiti-12    Fa0/3       1     0  Fa0/13       Up
6  00e0.1e9f.8c40 Surfers-12-1 Fa0/1       1     0  Fa0/9        Up
7  00e0.1e7e.be80 1900_Switch  3       0   1     0  Fa0/11       Up
8  00e0.1e9f.8300 Balboa       Fa0/11      2     5  Fa0/12       Up
9  0010.7bb6.1cc0 Ventura      Fa2/1       3     8  Fa0/24       Up
10 00e0.1e87.2140 2820-01      24      0   4     9  Fa2/3        Up

The following is sample output from the show cluster members for cluster member 3:

Switch# show cluster members 3
Device 'Surfers-24' with member number 3
        Device type:            cisco WS-C2924M-XL
        MAC address:            00e0.1e9f.9440
        Upstream MAC address:   00d0.796d.2e00 (Cluster member 0)
        Local port:             Fa0/18  FEC number:
        Upstream port:          Fa0/20  FEC Number:
        Hops from command device: 1

The following is sample output from the show cluster members detail command:

Switch# show cluster members detail
Device 'Tahiti-24' with member number 0 (Command Switch)
        Device type:            cisco WS-C3524-XL
        MAC address:            00d0.7964.1f00
        Upstream MAC address:
        Local port:                     FEC number: 
        Upstream port:                  FEC Number: 
        Hops from command device: 0
'Unknown'device with member number 1
        Device type: 
        MAC address: 
        Upstream MAC address:
        Local port:                     FEC number: 
        Upstream port:                  FEC Number: 
        Hops from command device: 255
Device 'Surfers-12-2' with member number 2
        Device type:            cisco WS-C3548-XL
        MAC address:            00d0.5868.f5c0
        Upstream MAC address:   00d0.7964.1f00 (Cluster member 0)
        Local port:             Fa0/7   FEC number: 1
        Upstream port:          Fa0/6   FEC Number: 
        Hops from command device: 1
Device 'Surfers-24' with member number 3
        Device type:            cisco WS-C3508G-XL
        MAC address:            00d0.7968.5380
        Upstream MAC address:   00d0.7964.1f00 (Cluster member 0)
        Local port:             Gi0/6   FEC number: 
        Upstream port:          Gi0/1   FEC Number: 
        Hops from command device: 1

show current

Use the show current VLAN database command to display the current VLAN database on the switch or a selected VLAN from it.

show current [vlan-id]

Syntax Description

vlan-id

(Optional) ID of the VLAN in the current database. If this variable is omitted, the entire VLAN database displays, included the pruning state and Version 2 mode.
Valid IDs are from 1 to 1005; do not enter leading zeroes.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

The following is sample output from the show current command. It displays the current VLAN database.

Switch(vlan)# show current
 
VLAN ISL Id: 1
    Name: default
    Media Type: Ethernet
    VLAN 802.10 Id: 100001
    State: Operational
    MTU: 1500
    Translational Bridged VLAN: 1002
    Translational Bridged VLAN: 1003
 
  VLAN ISL Id: 2
    Name: VLAN0002
    Media Type: Ethernet
    VLAN 802.10 Id: 100002
    State: Operational
    MTU: 1500
 
  VLAN ISL Id: 3
    Name: VLAN0003
    Media Type: Ethernet
    VLAN 802.10 Id: 100003
    State: Operational
    MTU: 4000 
 
VLAN ISL Id: 4
    Name: VLAN0004
    Media Type: Ethernet
    VLAN 802.10 Id: 100004
    State: Operational
    MTU: 1500
 
  VLAN ISL Id: 5
    Name: VLAN0005
    Media Type: Ethernet
    VLAN 802.10 Id: 100005
    State: Operational
    MTU: 1500
 
  VLAN ISL Id: 6
    Name: VLAN0006
    Media Type: Ethernet
    VLAN 802.10 Id: 100006
    State: Operational
    MTU: 1500

The following is sample output from the show current 2 command. It displays only VLAN 2 of the current database.

Switch(vlan)# show current 2
 
VLAN ISL Id: 2
    Name: VLAN0002
    Media Type: Ethernet
    VLAN 802.10 Id: 100002
    State: Operational
    MTU: 1500

Related Commands

Command Description

show changes

Displays the differences between the VLAN database currently on the switch and the proposed VLAN database.

show proposed

Displays the proposed VLAN database or a selected VLAN from it.

show env

Use the show env privileged EXEC command to display fan and temperature information for the 3524-PWR-XL switch.

show env {all | fan | temperature}

Syntax Description

all

Display both fan and temperature environmental status.

fan

Display the switch fan status.

temperature

Display the switch temperature status.

Command Modes

Privileged EXEC

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Examples

The following is sample output from the show env all command:

Switch# show env all
FAN 1 is OK
 
FAN 2 is OK
 
FAN 3 is OK
 
FAN 4 is OK
 
FAN 5 is OK
 
TEMPERATURE is OK

The following is sample output from the show env fans command:

FAN 1 is OK
 
FAN 2 is OK
 
FAN 3 is OK
 
FAN 4 is FAULTY
 
FAN 5 is OK

show file systems

Use the show file systems privileged EXEC command to display file system information.

show file systems

Syntax Description

The command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA5

This command was first introduced.

Examples

The following is sample output from the show file systems command:

Switch# show file systems
File Systems:
 
     Size(b)     Free(b)      Type  Flags  Prefixes
*    3612672     1234432     flash     rw   flash:
     3612672     1234432   unknown     rw   zflash:
           -           -    opaque     ro   bs:
       32768       30917     nvram     rw   nvram:
           -           -   network     rw   tftp:
           -           -    opaque     rw   null:
           -           -    opaque     rw   system:
           -           -   network     rw   rcp:

show interface

Use the show interface privileged EXEC command to display the administrative and operational status of a switching (nonrouting) port.

Syntax Description

interface-id

ID of the module and port number.

vlan number

VLAN number of the management VLAN. Valid IDs are from 1 to 1000.
Do not enter leading zeroes.

flow-control

Displays flowcontrol information for the specified port.

pruning

(Optional) Display pruning information for the trunk port.

switchport

(Optional) Display the administrative and operational status of a switching (nonrouting) port.

allowed-vlan---Display the VLAN IDs that receive and transmit all types of traffic on the trunk port. By default, all VLAN IDs are included.

prune-elig---Display the VLAN ID whose flood traffic can be pruned. By default, all VLANs, except VLAN 1 and 1002 through 1005, are pruning-eligible on the trunk.

native-vlan---Display the native VLAN ID for untagged traffic when the port is in 802.1Q trunking mode.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

11.2(8)SA5

The native-vlan keyword was added.

12.0(5)XP

The vlan number keyword was added.

12.0(5)XU

The pruning keyword was added.

Examples

The following is sample output from the show interface gi0/1 flow-control command.

Switch# show interface gi0/1 flow-control
Any,Input only

The display shows two values separated by a comma. The first value is the value you configured by using the flowcontrol command or through the Cluster Management Suite (or the default value if you did not configure it). The first value displayed can be one of the following settings:

None---Flow control is not enabled.
Asymmetric---Only the transmit or receive flow control is enabled.
Symmetric---Both the transmit and receive flow control are enabled.
Any---Any type of flow control is supported.

The second value in the display represents the flow control value that is autonegotiated with the link partner and can be one of the following settings:

None---Flow control with the link partner did not occur.
Output only---The interface can only transmit pause frames but not receive any.
Input only---The interface can only receive pause frames but not transmit any.
Output and Input---The interface can transmit and receive pause frames.

Note If you execute the show interface interface-id flow-control command on a GigaStack Gigabit Interface Converter (GBIC), the first value in the display is the setting for both GigaStack GBIC ports, and the second value is the autonegotiated setting for both ports.

The following is sample output from the show interface fa0/2 switchport command. Table 2-1 describes each field in the display.

Switch# show interface fa0/2 switchport
Name: fa0/2
Switchport: Enabled
Administrative Mode: Trunk
Operational Mode: Trunk
Administrative Trunking Encapsulation: ISL
Operational Trunking Encapsulation: ISL
Negotiation of Trunking: Disabled
Access Mode VLAN: 0 (inactive)
Trunking Native Mode VLAN: 1 (default)
Trunking VLANs Enabled: 1-30, 50, 100-1005
Trunking VLANs Active: 1-4
Pruning VLANs Enabled: 2-1001
 
Priority for untagged frames: 0
Voice VLAN: none
Appliance trust: none

Table 2-1: Show Interface fa0/2 Switchport Field Descriptions

Field Description

Name

Displays the port name.

Switchport

Displays the administrative and operational status of the port. In this display, the port is in switchport mode.

Administrative Mode

Operational Mode

Displays the administrative and operational mode.

Administrative Trunking Encapsulation

Operation Trunking Encapsulation

Negotiation of Trunking

Displays the administrative and operational encapsulation method. Also displays whether trunking negotiation is enabled.

Access Mode VLAN

Displays the VLAN ID to which the port is configured.

Trunking Native Mode VLAN

Trunking VLANs Enabled

Trunking VLANs Active

Lists the VLAN ID of the trunk that is in native mode. Lists the allowed VLANs on the trunk. Lists the active VLANs on the trunk.

Pruning VLANs Enabled

Lists the VLANs that are pruning-eligible.

Priority for untagged frames

Displays the port priority on incoming untagged frames.

Voice VLAN

Displays the voice VLAN.

Appliance trust

Displays how the appliance (telephone) connected to the specified port handles priority traffic received on its incoming port.

The following is sample output from the show interface fa0/9 pruning command when pruning is enabled in the VTP domain:

Switch# show interface fa0/9 pruning
Port    Vlans pruned for lack of request by neighbor
Fa0/9   3,4
 
Port    Vlans traffic requested of neighbor
Fa0/9   1-3

Related Commands

Command Description

switchport access

Configures a port as a static-access or dynamic-access port.

switchport mode

Configures the VLAN membership mode of a port.

switchport multi

Configures a list of VLANs to which the port is associated.

switchport priority default

Provides a default port priority for the incoming untagged frames.

switchport trunk pruning

Configures the VLAN pruning-eligible list for ports in trunking mode.

switchport voice vlan

Configures the voice VLAN on the port.

show mac-address-table

Use the show mac-address-table privileged EXEC command to display the MAC address table.

show mac-address-table [static | dynamic | secure | self | aging-time | count]
[address hw-addr] [interface interface] [atm slot/port] [vlan vlan-id]

Syntax Description

static

(Optional) Display only the static addresses.

dynamic

(Optional) Display only the dynamic addresses.

secure

(Optional) Display only the secure addresses.

self

(Optional) Display only addresses added by the switch itself.

aging-time

(Optional) Display aging-time for dynamic addresses for all VLANs.

count

(Optional) Display a count for different kinds of MAC addresses.

address hw-addr

(Optional) Display information for a specific address.

interface interface

(Optional) Display addresses for a specific port.

atm slot/port

(Optional) Add dynamic addresses to ATM module slot/port. Use 1 or 2 for the slot number. Use 0 as the port number.

vlan vlan-id

(Optional) Display addresses for a specific VLAN. Valid IDs are from
1 to 1005; do not enter leading zeroes.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA

This command was first introduced.

11.2(8)SA3

The self, aging-time, count, and vlan vlan-id keywords were added.

11.2(8)SA5

The atm slot/port keywords were added.

Usage Guidelines

This command displays the MAC address table for the switch. Specific views can be defined by using the optional keywords and values. If more than one optional keyword is used, then all of the conditions must be true in order for that entry to be displayed.

Examples

The following is sample output from the show mac-address-table command:

Switch# show mac-address-table
 
Dynamic Addresses Count:               9
Secure Addresses (User-defined) Count: 0
Static Addresses (User-defined) Count: 0
System Self Addresses Count:           41
Total MAC addresses:                   50
Non-static Address Table:
Destination Address  Address Type  VLAN  Destination Port
-------------------  ------------  ----  --------------------
0010.0de0.e289       Dynamic          1  FastEthernet0/1
0010.7b00.1540       Dynamic          2  FastEthernet0/5
0010.7b00.1545       Dynamic          2  FastEthernet0/5
0060.5cf4.0076       Dynamic          1  FastEthernet0/1
0060.5cf4.0077       Dynamic          1  FastEthernet0/1
0060.5cf4.1315       Dynamic          1  FastEthernet0/1
0060.70cb.f301       Dynamic          1  FastEthernet0/1
00e0.1e42.9978       Dynamic          1  FastEthernet0/1
00e0.1e9f.3900       Dynamic          1  FastEthernet0/1

Related Commands

Command Description

clear mac-address-table

Deletes entries from the MAC address table.

show ntp associations

Use the show ntp associations privileged EXEC command to display the status of Network Time Protocol (NTP) associations.

show ntp associations [detail]

Syntax Description

detail

(Optional) Show detailed information about each NTP association.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Examples

Detailed descriptions of the information displayed by this command can be found in the NTP specification RFC 1305.

The following is sample output from the show ntp associations command:

Switch# show ntp associations
     address         ref clock     st  when  poll reach  delay  offset    disp
 ~160.89.32.2      160.89.32.1       5    29  1024  377     4.2   -8.59     1.6
+~131.108.13.33    131.108.1.111     3    69   128  377     4.1    3.48     2.3
*~131.108.13.57    131.108.1.111     3    32   128  377     7.9   11.18     3.6
* master (synced), # master (unsynced), + selected, - candidate, ~ configured

show ntp status

Use the show ntp status EXEC command to display the status of Network Time Protocol (NTP).

show ntp status

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Examples

The following is sample output from the show ntp status command:

Switch# show ntp status
Clock is synchronized, stratum 4, reference is 131.108.13.57
nominal freq is 250.0000 Hz, actual freq is 249.9990 Hz, precision is 2**19
reference time is AFE2525E.70597B34 (00:10:22.438 PDT Mon Jul 5 1993)
clock offset is 7.33 msec, root delay is 133.36 msec
root dispersion is 126.28 msec, peer dispersion is 5.98 msec

show port block

Use the show port block privileged EXEC command to display the blocking of unicast or multicast flooding to a port.

show port block {unicast | multicast} [interface-id | vlan number]

Syntax Description

unicast

Display whether or not ports are blocking unicast packets.

multicast

Display whether or not ports are blocking multicast packets.

interface-id

(Optional) ID of the module and port number.

vlan number

(Optional) VLAN number from 1 to 1000. Do not enter leading zeroes.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines s

If the variable interface is omitted, the show port block unicast and show port block multicast commands display packet blocking information on all ports.

Examples

The following is sample output from the show port block command:

Switch# show port block unicast fa0/8
 
FastEthernet0/8 is blocked from unknown unicast addresses

Related Commands

Command Description

port block

Blocks the flooding of unknown unicast or multicast packets to a port.

show port group

Use the show port group privileged EXEC command to display the ports that belong to a port group.

show port group [group-number]

Syntax Description

group-number

(Optional) Port group to which the port is assigned.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

If the variable group-number is omitted, the show port group command displays all port groups on the switch.

Examples

The following is sample output from the show port group command:

Switch# show port group 1
 
Group  Interface
-----  ---------------
    1  FastEthernet0/1
    1  FastEthernet0/4

Related Commands

Command Description

port group

Assigns a port to a Fast EtherChannel or Gigabit EtherChannel port group.

show port led

Use the show port led privileged EXEC command to display the switch port LED colors.

show port led {interface} {duplex | inline-power | speed | status | util}

Syntax Description

interface

ID of the module and port number.

duplex

Display the duplex LED color.

inline-power

Display the inline-power LED color on the 3524-PWR switch. This keyword is available only on the 3524-PWR switch.

speed

Display the speed LED color.

status

Display the port status LED color.

util

Display the switch bandwidth utilization (see Table 2-2). This keyword is not available on the 3524-PWR switch.

Command Modes

Privileged EXEC

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

In the display output, BLACK means the corresponding switch LED is not lit; GREEN means the corresponding switch LED is green; AMBER means the corresponding switch LED is amber.

Examples

The following is sample output from the show port led fa0/8 duplex command:

Switch# show port led fa0/8 duplex
GREEN

Table 2-2 describes the possible display output for each keyword.

Table 2-2: Show Port LED Display Output Description

Keyword Description

duplex

BLACK: The port is operating in half-duplex mode.

GREEN: The port is operating in full-duplex mode.

inline-power

BLACK: Inline power is not being supplied.

GREEN: Inline power is being supplied.

speed

BLACK: The port is operating at 10 Mbps for 10/100 ports. The port is operating at 10 or 100 Mbps for 1000BaseX ports.

GREEN: The port is operating at 100 Mbps on 10/100 ports. The port is operating at 1000 Mbps for 1000BaseX ports.

status

BLACK: No link is present on the port.

GREEN: A link is present on the port.

AMBER: The port is not forwarding. The port was disabled by management (administratively down) or blocked by STP.

util

BLACK: If the show port led command for the right-most port displays BLACK and the show port led for all other ports displays GREEN, the switch is using from 25 to 49% of its total bandwidth.

If the show port led command for the two right-most ports displays BLACK, and the show port led for all other ports displays GREEN, the switch is using from 12 to 24% of its total capacity. If the three right-most ports display BLACK, then the utilization is from 6 to 11%, and so forth.

GREEN: If the show port led command displays GREEN on all ports, the switch is using 50% or more of its total bandwidth capacity.

show port monitor

Use the show port monitor privileged EXEC command to display the ports for which Switched Port Analyzer (SPAN) port monitoring is enabled.

show port monitor [interface-id | vlan number]

Syntax Description

interface-id

(Optional) ID of the module and port number enabled for SPAN.

vlan number

(Optional) VLAN number from 1 to 1000. Do not enter leading zeroes.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines

If the variable interface is omitted, the show port monitor command displays all monitor ports on the switch.

Examples

The following is sample output from the show port monitor command:

Switch# show port monitor fa0/8
 
Monitor Port        Port Being Monitored
------------------  --------------------
FastEthernet0/8     FastEthernet0/1
FastEthernet0/8     FastEthernet0/2
FastEthernet0/8     FastEthernet0/3
FastEthernet0/8     FastEthernet0/4

Related Commands

Command Description

port monitor

Enables SPAN port monitoring on a port.

show port network

Use the show port network privileged EXEC command to display the network port defined for the switch or VLAN.

show port network [interface-id | vlan number]

Syntax Description

interface-id

(Optional) ID of the module and port number.

vlan number

(Optional) VLAN number from 1 to 1000. Do not enter leading zeroes.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

If the variable interface is omitted, the show port network command displays all network ports on the switch.

Examples

The following is sample output from the show port network command:

Switch# show port network

Network Port      VLAN ID
------------      -------
FastEthernet0/11  1

Related Commands

Command Description

port network

Defines a port as the switch network port. All traffic with unknown unicast addresses is forwarded to the network port on the same VLAN.

show port protected

Use the show port protected privileged EXEC command to display the port protected mode for all ports.

show port protected

Syntax Description

This command has no keywords or options

Command Modes

Privileged EXEC

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Examples

The following is sample output from the show port protected command:

Switch# show port protected
 
FastEthernet0/3 is in protected mode
GigabitEthernet1/1 is in protected mode

Related Commands

Command Description

port protected

Isolates unicast, multicast, and broadcast traffic at Layer 2 from other protected ports on the same switch.

show port security

Use the show port security privileged EXEC command to display the port security settings defined for the port.

show port security [interface-id | vlan number]

Syntax Description

interface-id

(Optional) ID of the module and port number.

vlan number

(Optional) VLAN number from 1 to 1000. Do not enter leading zeroes.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines

If the variable interface is omitted, the show port security command displays all secure ports on the switch.

Examples

The following is sample output from the show port security command for fixed port 07:

Switch# show port security fa0/7
 
Secure Port      Secure Addr    Secure Addr  Security   Security Action
                 Cnt (Current)  Cnt (Max)    Reject Cnt
---------------  -------------  -----------  ---------- ----------------
FastEthernet0/7  0              132          0          Send Trap

Related Commands

Command Description

port security

Enables port security on a port.

show port storm-control

Use the show port storm-control privileged EXEC command to display the packet-storm control information. This command also displays the action that the switch takes when the thresholds are reached.

show port storm-control [interface] [{broadcast | multicast | unicast | history}]

Syntax Description

interface

(Optional) Port for which information is to be displayed.

broadcast

(Optional) Display broadcast storm information.

multicast

(Optional) Display multicast storm information.

unicast

(Optional) Display unicast storm information.

history

(Optional) Display storm history on a per-port basis.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA

This command was first introduced.

12.0(5)XU

The broadcast, multicast, unicast, and history keywords were added.

Usage Guidelines

If the variable interface is omitted, the show port storm-control command displays storm control settings on all ports on the switch.

You can display broadcast, multicast, or unicast packet-storm information by using the corresponding keyword.

Examples

The following is sample output from the show port storm-control command:

Switch# show port storm-control

Interface  Filter State   Trap State     Rising  Falling  Current  Traps Sent
---------  -------------  -------------  ------  -------  -------  ----------
Fa0/1      <inactive>     <inactive>       1000      200        0           0
Fa0/2      <inactive>     <inactive>        500      250        0           0
Fa0/3      <inactive>     <inactive>        500      250        0           0
Fa0/4      <inactive>     <inactive>        500      250        0           0

Related Commands

Command Description

port storm-control

Enables broadcast, multicast, or unicast storm control on a port.

show power inline

Use the show power inline privileged EXEC command to display the power status for the specified port or for all ports on the 3524-PWR-XL switch.

show power inline [interface-id] [actual | configured]

Syntax Description

interface-id

(Optional) ID of the module and port number.

actual

(Optional) Display the current power status, which might not be the same as the configured power.

configured

(Optional) Display the configured power status.

Command Modes

Privileged EXEC

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Examples

The following is sample output from the show power inline fa0/4 actual command:

Switch# show power inline fa0/4 actual
Interface            Power
-------------------- -----
FastEthernet0/4      no

Related Commands

Command Description

power inline

Determines how inline power is applied to devices on the specified Fast Ethernet port of the 3524-PWR-XL switch.

show proposed

Use the show proposed VLAN database command to display the proposed VLAN database or a selected VLAN from it.

show proposed [vlan-id]

Syntax Description

vlan-id

(Optional) ID of the VLAN in the proposed database. If this variable is omitted, the entire VLAN database displays, included the pruning state and Version 2 mode. Valid IDs are from 1 to 1005; do not enter leading zeroes.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

If the variable vlan-id is omitted, the show proposed command displays the entire proposed VLAN database.

The proposed VLAN database is not the running configuration until you use the exit or apply command.

Examples

The following is sample output from the show proposed command:

Switch(vlan)# show proposed
 
VLAN ISL Id: 1
    Name: default
    Media Type: Ethernet
    VLAN 802.10 Id: 100001
    State: Operational
    MTU: 1500
    Translational Bridged VLAN: 1002
    Translational Bridged VLAN: 1003
 
  VLAN ISL Id: 2
    Name: VLAN0002
    Media Type: FDDI Net
    VLAN 802.10 Id: 100002
    State: Operational
    MTU: 1500
    STP Type: IBM
 
VLAN ISL Id: 1002
    Name: fddi-default
    Media Type: FDDI
    VLAN 802.10 Id: 101002
    State: Operational
    MTU: 1500
    Bridge Type: SRB
    Translational Bridged VLAN: 1
    Translational Bridged VLAN: 1003
 
VLAN ISL Id: 1003
    Name: trcrf-default
    Media Type: TRCRF
    VLAN 802.10 Id: 101003
    State: Operational
    MTU: 4472
    Bridge Type: SRB
    Ring Number: 3276
    Bridge Number: 1
    Parent VLAN: 1005
    Maximum ARE Hop Count: 7
    Maximum STE Hop Count: 7
    Backup CRF Mode: Disabled
    Translational Bridged VLAN: 1
    Translational Bridged VLAN: 1002
 
  VLAN ISL Id: 1004
    Name: fddinet-default
    Media Type: FDDI Net
    VLAN 802.10 Id: 101004
    State: Operational
    MTU: 1500
    Bridge Type: SRB
    Bridge Number: 1
    STP Type: IBM
 
VLAN ISL Id: 1005
    Name: trbrf-default
    Media Type: TRBRF
    VLAN 802.10 Id: 101005
    State: Operational
    MTU: 4472
    Bridge Type: SRB
    Bridge Number: 15
    STP Type: IBM

Related Commands

Command Description

show changes

Displays the differences between the VLAN database currently on the switch and the proposed VLAN database.

show current

Displays the current VLAN database on the switch or a selected VLAN from it.

show rps

Use the show rps privileged EXEC command to display the status of the Cisco Redundant Power System (RPS).

show rps

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Examples

The following is sample output from the show rps command. Table 2-3 describes the possible display output.

Switch# show rps
ACTIVATED

Table 2-3: Show RPS Display Output Description

Display Description Switch RPS LED Color

NA

The RPS is off or not installed.

Off (all switch and RPS models)

ACTIVATED

The internal power supply of the switch is down. The switch is operating through the RPS.

Blinking amber (3524-PWR switch connected to RPS 300)

Solid green (all 2900 XL and 3500 XL switches, except the 3524-PWR, connected to the Cisco RPS)

DEACTIVATED

The RPS is connected, operational, and in standby mode. The switch is operating from its own internal power supply.

Solid green (3524-PWR switch connected to RPS 300)

Blinking green (all 2900 XL and 3500 XL switches, except the 3524-PWR, connected to the Cisco RPS)

FAULTY

The RPS is connected but not operating correctly (faulty). One of the power supplies in the RPS could be powered down or a fan on the RPS could have failed.

Solid amber (all switch and RPS models)

NOT AVAILABLE (only for 3524-PWR switch)

The RPS is backing up another switch; power redundancy is lost.

Blinking green (3524-PWR switch connected to RPS 300)

show spanning-tree

Use the show spanning-tree privileged EXEC command to display spanning-tree information for the specified spanning-tree instances.

show spanning-tree [vlan stp-list] [interface interface-list]

Syntax Description

vlan stp-list

(Optional) List of spanning-tree instances. Each spanning-tree instance is associated with a VLAN ID. Enter each VLAN ID separated by a space. Valid IDs are from 1 to 1005; do not enter leading zeroes.
Ranges are not supported.

interface interface-list

List of ports for which spanning-tree information is displayed. Enter each port separated by a space. Ranges are not supported.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

If the variable stp-list is omitted, the command applies to the Spanning Tree Protocol (STP) instance associated with VLAN 1.

Examples

The following is sample output from the show spanning-tree command for VLAN 1:

Switch# show spanning-tree vlan 1
 
Spanning tree 1 is executing the IEEE compatible Spanning Tree protocol
  Bridge Identifier has priority 32768, address 00e0.1eb2.ddc0
  Configured hello time 2, max age 20, forward delay 15
  Current root has priority 32768, address 0010.0b3f.ac80
  Root port is 5, cost of root path is 10
  Topology change flag not set, detected flag not set, changes 1
  Times:  hold 1, topology change 35, notification 2
          hello 2, max age 20, forward delay 15
  Timers: hello 0, topology change 0, notification 0
 
Interface Fa0/1  in Spanning tree 1 is down
   Port path cost 100, Port priority 128
   Designated root has priority 32768, address 0010.0b3f.ac80
   Designated bridge has priority 32768, address 00e0.1eb2.ddc0
   Designated port is 1, path cost 10
   Timers: message age 0, forward delay 0, hold 0
   BPDU: sent 0, received 0 
...

The following is sample output from the show spanning-tree interface command for port 3:

Switch# show spanning-tree interface fa0/3
 
Interface Fa0/3 (port 3) in Spanning tree 1 is down
   Port path cost 100, Port priority 128
   Designated root has priority 6000, address 0090.2bba.7a40
   Designated bridge has priority 32768, address 00e0.1e9f.4abf
   Designated port is 3, path cost 410
   Timers: message age 0, forward delay 0, hold 0
   BPDU: sent 0, received 0

Related Commands

Command Description

spanning-tree

Enables STP on a VLAN.

spanning-tree forward-time

Sets the forwarding-time for the specified spanning-tree instances.

spanning-tree max-age

Changes the interval between messages the spanning tree receives from the root switch.

spanning-tree port-priority

Configures a port priority, which is used when two switches tie for position as the root switch.

spanning-tree protocol

Specifies the STP to be used for specified spanning-tree instances.

show tacacs

Use the show tacacs privileged EXEC command to display various Terminal Access Controller Access Control System Plus (TACACS+) server statistics.

show tacacs

Syntax Description

This command has no arguments.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Examples

The following is sample output from the show tacacs command:

Switch# show tacacs
 
Server:172.20.128.113/49:opens=4 closes=4 aborts=0 errors=0
        packets in=6 packets out=6
        no connection

show udld

Use the show udld user EXEC command to display UniDirectional Link Detection (UDLD) status for all ports or the specified port.

show udld [interface-id]

Syntax Description

interface-id

(Optional) ID of the module and port number or a VLAN ID. Valid IDs are from 1 to 1000.

Command Modes

User EXEC

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Examples

The following is sample output from the show udld fa0/11 command. For this display, UDLD is enabled on both ends of the link, and UDLD detects that the link is bidirectional. Table 2-4 describes the fields in this display.

Switch# show udld fa0/11
Interface Fa0/11
Port enable configuration setting: Follows global setting
Operational enable state: Enabled
Current bidirectional state: Bidirectional
Message interval: 60
Message timer: 38
Current operational state: Advertisement
Time out interval: 5
Time out timer: 0
Restart counter: 0
Neighbors counter: 1
Probe counter: 0
No multiple neighbors detected
Current pool id: 1
    ---
    Cache entry 1 (0x69D8E4)
    Device name: aunguyen-1.cisco.com
    Device MAC address: 00:E0:1E:9F:85:80
    Port ID: Fa1/1
    Expiration time: 159
    Cache device ID: 1
    Resynch flag clear
    Current neighbor state: Bidirectional
    Most recent message type received: Probe
    Message interval: 5
        Neighbor echo 1 device: 00:50:0F:08:A4:00
        Neighbor echo 1 port: Fa0/11

Table 2-4: Show Udld Field Descriptions

Field Description

Interface

The interface on the local device configured for UDLD.

Port enable configuration setting

How UDLD is configured on the port. If UDLD is enabled or disabled, the port enable configuration setting is the same as operational enable state. Otherwise, the enable operational setting depends on the global enable setting.

Operational enable state

Operational state that indicates whether UDLD is actually running on this port.

Current bidirectional state

The bidirectional state of the link. An unknown state is displayed if the link is down or if it is connected to an UDLD-incapable device. A bidirectional state is displayed if the link is a normal two-way connection to a UDLD-capable device. All other values indicate miswiring.

Message interval

How often advertisement messages are sent from the local device. Measured in seconds.

Message timer

The length of time before the next advertisement is sent from the local device. Measured in seconds.

Current operational state

The current phase of the UDLD state machine. For a normal bidirectional link, the state machine is most often in the Advertisement phase.

Time out interval

The time period, in seconds, that UDLD waits for echoes from a neighbor device during the detection window.

Time out timer

The remaining time in seconds in the detection window. This setting is meaningful only if UDLD is in the detection phase.

Restart counter

The number of times UDLD sends probe messages in the detection phase.

Neighbors counter

The number of neighbors detected. For point-to-point links, this value should always be one. It is greater than one only when the port is connected to a hub.

Probe counter

The remaining number of probe messages to send in the current detection window. This setting is meaningful only if UDLD is in the detection phase.

Current pool id

An internal index number on the local device.

Cache entry 1

Information from the first cache entry, which contains a copy of echo information received from the neighbor.

Device name

The neighbor device name.

Device MAC address

The neighbor MAC address.

Port ID

The neighbor port ID enabled for UDLD.

Expiration time

The amount of time in seconds remaining before this cache entry is aged out.

Cache device ID

The ID of the cache device.

Resynch flag clear

Indicates that there are no outstanding requests from neighbors to resynchronize cache data.

Current neighbor state

The neighbor's current state. If both the local and neighbor devices are running UDLD normally, the neighbor state and local state should be bidirectional. If the link is down or the neighbor is not UDLD-capable, no cache entries are displayed.

Most recent message type received

The type of message received from the neighbor.

Message interval

The rate, in seconds, at which the neighbor is sending advertisement messages.

Neighbor echo 1 device

The MAC address of the neighbors neighbor from which the echo originated.

Neighbor echo 1 port

The port number ID of the neighbor from which the echo originated.

Related Commands

Command Description

udld

Enables UDLD on a port.

udld enable

Enables UDLD on all ports on the switch.

udld reset

Resets any interface that has been shut down by UDLD.

show version

Use the show version privileged EXEC command to display version information for the hardware and firmware.

show version

Syntax Description

The command has no arguments

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Examples

The following is sample output from the show version command:

Switch# show version
 
Cisco Internetwork Operating System Technology Software
IOS Technology(tm) C3500XL Software (C3500XL-C3H2S-M), Version 12.0
Copyright (c) 1986-1998 by cisco Systems, Inc.
Compiled Mon 22-Nov-99 10:51 by mollyn
Image text-base: 0x00003000, data-base: 0x0031B6B4
 
ROM: Bootstrap program is C3500XL boot loader
 
Switch uptime is 1 hour, 32 minutes
System returned to ROM by reload
System image file is "flash:c3500XL-c3h2s-mz-120.0.0.29-XU.bin" 
 
cisco WS-C3524-XL (PowerPC403) processor (revision 0x01) with 8192K/1024K bytes
of memory.
Processor board ID 0x12, with hardware revision 0x00
Last reset from warm-reset 
 
Processor is running Enterprise Edition Software
Cluster command switch capable
Cluster member switch capable
24 FastEthernet/IEEE 802.3 interface(s) 
2 Gigabit Ethernet/IEEE 802.3 interface(s)
 
32K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address: 00:D0:79:6D:2F:00
Motherboard assembly number: 73-3904-08
Power supply part number: 34-0851-02
Motherboard serial number: FAA03269NLK
Power supply serial number: PHI031200D2
Model revision number: A0
Model number: WS-C3524-XL-A
System serial number: FAA0328K01G
Configuration register is 0xF

show vlan

Use the show vlan privileged EXEC command to display the parameters for all configured VLANs or one VLAN (if the VLAN ID or name is specified) in the administrative domain.

show vlan [brief | id vlan-id | name vlan-name]

Syntax Description

brief

(Optional) Display one line for each VLAN with the VLAN name, status, and its ports

id vlan-id

(Optional) ID of the VLAN displayed. Valid IDs are from 1 to 1005; do not enter leading zeroes.

name vlan-name

(Optional) Name of the VLAN displayed. The VLAN name is an ASCII string from 1 to 32 characters.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

11.2(8)SA4

The name vlan-name keywords were added.

Examples

The following is sample output from the show vlan command:

Switch# show vlan
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/2, Fa0/3, Fa0/4,
                                                Fa0/5, Fa0/6, Fa0/7, Fa0/8,
                                                Fa0/9, Fa0/10, Fa0/11, Fa0/12,
                                                Fa0/13, Fa0/14, Fa0/15, Fa0/16,
                                                Fa0/17, Fa0/18, Fa0/19, Fa0/20,
                                                Fa0/21, Fa0/22, Fa0/23, Fa0/24,
                                                Gi0/1, Gi0/2
1002 fddi-default                     active    
1003 token-ring-default               active    
1004 fddinet-default                  active    
1005 trnet-default                    active 
 
VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- ------ ------
1    enet  100001     1500  -      -      -        -    1002   1003
6    fdnet 100006     1500  -      -      -        ieee 0      0
7    trnet 100007     1500  -      -      5        ieee 0      0
1002 fddi  101002     1500  -      -      -        -    1      1003
1003 tr    101003     1500  1005   3276   -        -    1      1002
1004 fdnet 101004     1500  -      -      1        ibm  0      0
1005 trnet 101005     1500  -      -      15       ibm  0      0

The following is sample output from the show vlan brief command:

Switch# show vlan brief
 
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/2, Fa0/5, Fa0/6,
                                                Fa0/7, Fa0/8, Fa0/9, Fa0/10,
                                                Fa0/11, Fa0/12, Fa0/13, Fa0/14,
                                                Fa0/15, Fa0/16, Fa1/1, Fa1/2,
                                                Fa1/3, Fa1/4, Fa2/3, Fa2/4
2    VLAN0002                         active
3    VLAN0003                         active
6    VLAN0006                         active
7    VLAN0007                         active
1002 fddi-default                     active
1003 token-ring-default               active
1004 fddinet-default                  active
1005 trnet-default                    active

The following is sample output from the show vlan id 6 or show vlan name VLAN006 command:

Switch# show vlan id 6
 
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
6    VLAN0006                         active
 
VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- ------ ------
6    fdnet 100006     1500  -      -      -        ieee 0      0

Related Commands

Command Description

switchport mode

Configures the VLAN membership mode of a port.

vlan

Configures VLAN characteristics.

show vmps

Use the show vmps privileged EXEC command to display the VLAN Query Protocol (VQP) version, reconfirmation interval, retry count, VLAN Membership Policy Server (VMPS) IP addresses, and the current and primary servers.

show vmps

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

The following is sample output from the show vmps command:

Switch# show vmps
 
VQP Client Status:
--------------------
VMPS VQP Version:   1
Reconfirm Interval: 60 min
Server Retry Count: 3
VMPS domain server: 172.20.128.86 (primary, current)
                    172.20.128.87 
 
Reconfirmation status
---------------------
VMPS Action:         No Dynamic Port

Related Commands

Command Description

vmps reconfirm

Sends VQP queries to reconfirm all dynamic VLAN assignments with the VMPS.

vmps retry

Configures the per-server retry count for the VQP client.

vmps server

Configures the primary VMPS and up to three secondary servers.

show vmps statistics

Use the show vmps statistics privileged EXEC command to display the VLAN Query Protocol (VQP) client-side statistics and counters.

show vmps statistics

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

This following is sample output from the show vmps statistics command. Table 2-5 describes each field in the display.

Switch# show vmps statistics
 
VMPS Client Statistics
----------------------
VQP  Queries:               0
VQP  Responses:             0
VMPS Changes:               0
VQP  Shutdowns:             0
VQP  Denied:                0
VQP  Wrong Domain:          0
VQP  Wrong Version:         0
VQP  Insufficient Resource: 0

Table 2-5: Show VMPS Statistics Field Descriptions

Field Description

VQP Queries

Number of queries sent by the client to the VLAN Membership Policy Server (VMPS).

VQP Responses

Number of responses sent to the client from the VMPS.

VMPS Changes

Number of times that the VMPS changed from one server to another.

VQP Shutdowns

Number of times the VMPS sent a response to shutdown the port. The client disables the port and removes all dynamic addresses on this port from the address table. You must administratively reenable the port to restore connectivity.

VQP Denied

Number of times the VMPS denied the client request for security reasons. When the VMPS response says to deny an address, no frame is forwarded to or from the workstation with that address (broadcast or multicast frames are delivered to the workstation if the port has been assigned to a VLAN). The client keeps the denied address in the address table as a blocked address to prevent further queries from being sent to the VMPS for each new packet received from this workstation. The client ages the address if no new packets are received from this workstation on this port within the aging time period.

VQP Wrong Domain

Number of times the management domain in the request does not match the one for the VMPS. Any previous VLAN assignments of the port are not changed. Receipt of this response indicates that the server and the client have not been configured with the same VTP management domain.

VQP Wrong Version

Number of times the version field in the query packet contains a value that is higher than the version supported by the VMPS. Previous VLAN assignment of the port is not changed. The switches send only VMPS version 1 requests.

VQP Insufficient Resource

Number of times the VMPS is unable to answer the request because of a resource availability problem. If the retry limit has not yet been reached, the client repeats the request with the same server or with the next alternate server, depending on whether the per-server retry count has been reached.

Related Commands

Command Description

clear vmps statistics

Clears the statistics maintained by the VQP client.

show vtp

Use the show vtp privileged EXEC command to display general information about the VLAN Trunk Protocol (VTP) management domain, status, and counters.

show vtp {counters | status}

Syntax Description

counters

Display the VTP counters for the switch.

status

Display general information about the VTP management domain.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

The following is sample output from the show vtp counters command. Table 2-6 describes each field in the display.

Switch# show vtp counters
 
VTP statistics:
Summary advertisements received    : 38
Subset advertisements received     : 0
Request advertisements received    : 0
Summary advertisements transmitted : 13
Subset advertisements transmitted  : 3
Request advertisements transmitted : 0
Number of config revision errors   : 0
Number of config digest errors     : 0
Number of V1 summary errors        : 0
 
 
VTP pruning statistics:
 
Trunk            Join Transmitted Join Received    Summary advts received from
                                                   non-pruning-capable device
---------------- ---------------- ---------------- ---------------------------
Fa0/9               827              824              0
Fa0/10              827              823              0 
Fa0/11              827              823              0

Table 2-6: Show VTP Counters Field Descriptions

Field Description

Summary Advts Received

Number of summary advertisements received by this switch on its trunk ports. Summary advertisements contain the management domain name, the configuration revision number, the update timestamp and identity, the authentication checksum, and the number of subset advertisements to follow.

Subset Advts Received

Number of subset advertisements received by this switch on its trunk ports. Subset advertisements contain all the information for one or more VLANs.

Request Advts Received

Number of advertisement requests received by this switch on its trunk ports. Advertisement requests normally request information on all VLANs. They can also request information on a subset of VLANs.

Summary Advts Transmitted

Number of summary advertisements sent by this switch on its trunk ports. Summary advertisements contain the management domain name, the configuration revision number, the update timestamp and identity, the authentication checksum, and the number of subset advertisements to follow.

Subset Advts Transmitted

Number of subset advertisements sent by this switch on its trunk ports. Subset advertisements contain all the information for one or more VLANs.

Request Advts Transmitted

Number of advertisement requests sent by this switch on its trunk ports. Advertisement requests normally request information on all VLANs. They can also request information on a subset of VLANs.

No. of Configuration Revision Errors

Number of revision errors.

Whenever you define a new VLAN, delete an existing one, suspend or resume an existing VLAN, or modify the parameters on an existing VLAN, the configuration revision number of the switch increments.

Revision errors increment whenever the switch receives an advertisement whose revision number matches the revision number of the switch, but the MD5 digest values do not match. This error indicates that the VTP password in the two switches is different, or the switches have different configurations.

These errors indicate that the switch is filtering incoming advertisements, which causes the VTP database to become unsynchronized across the network.

No. of Configuration Digest Errors

Number of MD5 digest errors.

Digest errors increment whenever the MD5 digest in the summary packet and the MD5 digest of the received advertisement calculated by the switch do not match. This error usually indicates that the VTP password in the two switches is different. To solve this problem, make sure the VTP password on all switches is the same.

These errors indicate that the switch is filtering incoming advertisements, which causes the VTP database to become unsynchronized across the network.

No. of V1 Summary Errors

Number of version 1 errors.

Version 1 summary errors increment whenever a switch in VTP V2 mode receives a VTP version 1 frame. These errors indicate that at least one neighboring switch is either running VTP version 1 or VTP version 2 with V2-mode disabled. To solve this problem, change the configuration of the switches in VTP V2-mode to disabled.

Join Transmitted

Number of VTP pruning messages transmitted on the trunk.

Join Received

Number of VTP pruning messages received on the trunk.

Summary Advts Received from non-pruning-capable device

Number of VTP summary messages received on the trunk from devices that do not support pruning.

The following is sample output from the show vtp status command. Table 2-7 describes each field in the display.

Switch# show vtp status
 
VTP Version                     : 2
Configuration Revision          : 1
Maximum VLANs supported locally : 68
Number of existing VLANs        : 7
VTP Operating Mode              : Server
VTP Domain Name                 : test1
VTP Pruning Mode                : Disabled
VTP V2 Mode                     : Disabled
VTP Traps Generation            : Disabled
MD5 digest                      : 0x3D 0x02 0xD4 0x3A 0xC4 0x46 0xA1 0x03
Configuration last modified by 172.20.130.52 at 3-4-93 22:25:

Table 2-7: Show VTP Status Field Descriptions

Field Description

VTP Version

Displays the VTP version operating on the switch. By default,
2900 and 3500 XL switches implement version 1 but can be set to
version 2.

Configuration Revision

Current configuration revision number on this switch.

Maximum VLANs Supported Locally

Maximum number of VLANs supported locally.

Number of Existing VLANs

Number of existing VLANs.

VTP Operating Mode

Displays the VTP operating mode, which can be server, client, or transparent.

Server: a switch in VTP server mode is enabled for VTP and sends advertisements. You can configure VLANs on it. The switch guarantees that it can recover all the VLAN information in the current VTP database from nonvolatile storage after reboot. By default, every switch is a VTP server.

Client: a switch in VTP client mode is enabled for VTP, can send advertisements, but does not have enough nonvolatile storage to store VLAN configurations. You cannot configure VLANs on it. When a VTP client starts up, it does not transmit VTP advertisements until it receives advertisements to initialize its VLAN database.

Transparent: a switch in VTP transparent mode is disabled for VTP, does not transmit advertisements or learn from advertisements sent by other devices, and cannot affect VLAN configurations on other devices in the network. The switch receives VTP advertisements and forwards them on all trunk ports except the one on which the advertisement was received. The configuration of multi-VLAN ports causes the switch to automatically enter transparent mode.

Note Catalyst 2912MF, 2924M, and 3500 XL switches support up to 250 VLANs. All other 2900 XL switches support up to 64 VLANs. If you define more than 250 or 64 or if the switch receives an advertisement that contains more than 250 or 64 VLANs, the switch automatically enters VTP transparent mode and operates with the VLAN configuration preceding the one that sent it into transparent mode.

VTP Domain Name

Name that identifies the administrative domain for the switch.

VTP Pruning Mode

Displays whether pruning is enabled or disabled. Enabling pruning on a VTP server enables pruning for the entire management domain. Pruning restricts flooded traffic to those trunk links that the traffic must use to access the appropriate network devices.

VTP V2 Mode

Displays if VTP version 2 mode is enabled. All VTP version 2 switches operate in version 1 mode by default. Each VTP switch automatically detects the capabilities of all the other VTP devices. A network of VTP devices should be configured to version 2 only if all VTP switches in the network can operate in version 2 mode.

VTP Traps Generation

Displays whether VTP traps are transmitted to a network management station.

MD5 Digest

A 16-byte checksum of the VTP configuration.

Configuration Last Modified

Displays the date and time of the last configuration modification. Displays the IP address of the switch that caused the configuration change to the database.

Related Commands

Command Description

clear vtp counters

Clears the VTP and pruning counters.

vtp

Configures the VTP mode.

shutdown

Use the shutdown interface configuration command to disable a port and to shutdown the management VLAN. Use the no form of this command to restart a disabled port or to activate the management VLAN.

shutdown

no shutdown

Syntax Description

This command has no arguments or keywords.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

12.0(5)XP

Command functionality extended to the management VLAN interface.

Usage Guidelines

The shutdown command for a port causes it to stop forwarding. You can enable the port with the no shutdown command.

The no shutdown command has no effect if the port is a static-access port assigned to a VLAN that has been deleted, suspended, or shut down. The port must first be a member of an active VLAN before it can be reenabled.

Only one management VLAN interface can be active at a time. The remaining VLANs are shut down. In the show running-config command, the active management VLAN interface is the one with the shutdown command displayed.

Examples

The following examples show how to disable fixed port fa0/8 and how to reenable it:

Switch(config)# interface fa0/8
Switch(config-if)# shutdown
 
Switch(config-if)# no shutdown

You can verify the previous commands by entering the show interface command in privileged EXEC mode.

Related Commands

Command Description

management

Shuts down the current management VLAN interface and enables the new management VLAN interface.

shutdown vlan

Use the shutdown vlan global configuration command to shut down (suspend) local traffic on the specified VLAN. Use the no form of this command to restart local traffic on the VLAN.

shutdown vlan vlan-id

no shutdown vlan vlan-id

Syntax Description

vlan-id

ID of the VLAN to be locally shut down. Valid IDs are from 2 to 1001, excluding VLANs defined as default VLANs under the VLAN Trunk Protocol (VTP).
The default VLANs are 1 and 1002-1005. Do not enter leading zeroes.

Defaults

No default is defined.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

The shutdown vlan command does not change the VLAN information in VTP database. It shuts down traffic locally, but the switch still advertises VTP information.

Examples

The following example shows how to shutdown traffic on VLAN 2:

Switch(config)# shutdown vlan 2

You can verify the previous command by entering the show vlan command in privileged EXEC mode.

Related Commands

Command Description

abort

Abandons the proposed new VLAN database, exits VLAN database mode, and returns to privileged EXEC mode.

apply

Implements the proposed new VLAN database, increments the database configuration revision number, propagates it throughout the administrative domain, and remains in VLAN database mode.

exit

Implements the proposed new VLAN database, increments the database configuration number, propagates it throughout the administrative domain, and returns to privileged EXEC mode.

reset

Abandons the proposed VLAN database and remains in VLAN database mode. Resets the proposed database to the currently implemented VLAN database on the switch.

vlan database

Enters VLAN database mode from the command-line interface (CLI).

snmp-server enable traps vlan-membership

Use the snmp-server enable traps vlan-membership global configuration command to enable SNMP notification for VLAN Membership Policy Server (VMPS) changes. Use the no form of this command to disable the VMPS trap notification.

snmp-server enable traps vlan-membership

no snmp-server enable traps vlan-membership

Syntax Description

This command has no arguments or keywords.

Defaults

SNMP traps for VMPS are disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

Specify the host that receives the traps by using the snmp-server host command.

Examples

The following example shows how to enable VMPS to send trap notifications:

Switch(config)# snmp-server enable trap vlan-membership

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

snmp-server host

Specifies the host that receives SNMP traps.

snmp-server enable traps vtp

Use the snmp-server enable traps vtp global configuration command to enable SNMP notification for VLAN Trunk Protocol (VTP) changes. Use the no form of this command to disable VTP trap notification.

snmp-server enable traps vtp

no snmp-server enable traps vtp

Syntax Description

This command has no arguments or keywords.

Defaults

SNMP traps for VTP are disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

Specify the host that receives the traps by using the snmp-server host command.

Examples

The following example shows how to enable VTP to send trap notifications:

Switch(config)# snmp-server enable trap vtp

You can verify the previous command by entering the show vtp status or show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

show vtp status

Displays general information about the VTP management domain and status.

snmp-server host

Specifies the host that receives SNMP traps.

snmp-server host

Use the snmp-server host global configuration command to specify the host that receives SNMP traps. Use the no form of this command to remove the specified host.

Syntax Description

host-address

IP address or name of the SNMP trap host.

community-string

Password-like community string sent with the trap operation

c2900

(Optional) Send SNMP 2900 XL or 3500 XL switch traps.

config

(Optional) Send SNMP configuration traps.

snmp

(Optional) Send SNMP-type traps.

tty

(Optional) Send Cisco enterprise-specific traps when a Transmission Control Protocol (TCP) connection closes

udp-port port-number

(Optional) UDP port of the host to use. The default is 162.

vlan-membership

(Optional) Send SNMP VLAN Membership Policy Server (VMPS) traps

vtp

(Optional) Send SNMP VLAN Trunk Protocol (VTP) traps.

Defaults

The SNMP trap host address and community string are not defined.

Traps are disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

Use the snmp-server host command with the snmp-server enable traps commands to generate traps.

Examples

The following example shows how to configure an SNMP host to receive VTP traps:

Switch(config)# snmp-server host 172.20.128.178 traps vtp

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

snmp-server enable traps vlan-membership

Enables SNMP notification for VMPS changes.

snmp-server enable traps vtp

Enables SNMP notification for VTP changes.

spanning-tree

Use the spanning-tree global configuration command to enable Spanning Tree Protocol (STP) on a VLAN. Use the no form of the command to disable STP on a VLAN.

spanning-tree [vlan stp-list]

no spanning-tree [vlan stp-list]

Defaults

STP is enabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

Disabling STP causes the VLAN or list of VLANs to stop participating in STP. Ports that are administratively down remain down. Received Bridge Protocol Data Units (BPDUs) are forwarded like other multicast frames. The VLAN does not detect and prevent loops when STP is disabled.

You can disable STP on a VLAN that is not currently active, and verify the change by using the privileged EXEC show running-config or the show spanning-tree vlan stp-list command. The setting takes effect when the VLAN is activated.

If the variable stp-list is omitted, the command applies to the STP instance associated with VLAN 1.

You can enable STP on a VLAN that has no ports assigned to it.

Examples

The following example shows how to disable STP on VLAN 5:

Switch(config)# no spanning-tree vlan 5

You can verify the previous command by entering the show spanning-tree command in privileged EXEC mode. In this instance, VLAN 5 does not appear in the list.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree forward-time

Sets the forwarding-time for the specified spanning-tree instances.

spanning-tree max-age

Changes the interval between messages the spanning tree receives from the root switch.

spanning-tree port-priority

Configures a port priority, which is used when two switches tie for position as the root switch.

spanning-tree protocol

Specifies the STP protocol to be used for specified spanning-tree instances.

spanning-tree cost

Use the spanning-tree cost interface configuration command to set the path cost for Spanning Tree Protocol (STP) calculations. In the event of a loop, spanning tree considers the path cost when selecting an interface to place into the forwarding state. Use the no form of this command to return to the default value.

spanning-tree [vlan stp-list] cost cost

no spanning-tree [vlan stp-list] cost

Syntax Description

vlan stp-list

(Optional) List of spanning-tree instances. Each spanning-tree instance is associated with a VLAN ID. Valid IDs are from 1 to 1005. Enter each VLAN ID separated by a space. Do not enter leading zeroes. Ranges are not supported.

cost

Path cost can range from 1 to 65535, with higher values indicating higher costs. This range applies whether or not the IEEE STP has been specified

Defaults

The default path cost is computed from the interface bandwidth setting. The following are IEEE default path cost values:

10 Mbps - 100
100 Mbps - 19
155 Mbps - 14
1 Gbps - 4
10 Gbps - 2
Speeds greater than 10 Gbps - 1

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

If the variable stp-list is omitted, the command applies to the STP instance associated with VLAN 1.

You can set a cost for a port or on a VLAN that does not exist. The setting takes effect when the VLAN exists.

Examples

The following example shows how to set a path cost value of 250 for VLAN 1:

Switch(config-if)# spanning-tree vlan 1 cost 250

You can verify the previous command by entering the show spanning-tree command in privileged EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree portfast

Enables the Port Fast feature on a port in all its associated VLANs.

spanning-tree priority

Configures the switch priority for the specified spanning-tree instance.

spanning-tree forward-time

Use the spanning-tree forward-time global configuration command to set the forwarding-time for the specified spanning-tree instances. The forwarding time determines how long each of the listening and learning states last before the port begins forwarding. Use the no form of this command to return to the default value.

spanning-tree [vlan stp-list] forward-time seconds

no spanning-tree [vlan stp-list] forward-time

Syntax Description

vlan stp-list

(Optional) List of spanning-tree instances. Each spanning-tree instance is associated with a VLAN ID. Valid IDs are from 1 to 1005. Enter each VLAN ID separated by a space. Do not enter leading zeroes. Ranges are not supported.

seconds

Forward-delay interval from 4 to 200 seconds.

Defaults

The default forwarding-time for IEEE Spanning Tree Protocol (STP) is 15 seconds. The default for IBM STP is 4 seconds.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

If the variable stp-list is omitted, the command applies to the STP instance associated with VLAN 1.

You can set the forwarding-time on a VLAN that has no ports assigned to it. The setting takes effect when you assign ports to it.

Examples

The following example shows how to set the spanning-tree forwarding time to 18 seconds for VLAN 20:

Switch(config)# spanning-tree vlan 20 forward-time 18

You can verify the previous command by entering the show spanning-tree command in privileged EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree max-age

Changes the interval between messages the spanning tree receives from the root switch.

spanning-tree port-priority

Configures a port priority, which is used when two switches tie for position as the root switch.

spanning-tree protocol

Specifies the STP protocol to be used for specified spanning-tree instances.

spanning-tree hello-time

Use the spanning-tree hello-time global configuration command to specify the interval between hello Bridge Protocol Data Units (BPDUs). Use the no form of this command to return to the default interval.

spanning-tree [vlan stp-list] hello-time seconds

no spanning-tree [vlan stp-list] hello-time

Defaults

The default hello time for IEEE Spanning Tree Protocol (STP) and IBM STP is 2 seconds.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

If the variable stp-list is omitted, the command applies to the STP instance associated with VLAN 1.

You can set the hello time on a VLAN that has no ports assigned to it. The setting takes effect when you assign ports to it.

Examples

The following example shows how to set the spanning-tree hello-delay time to 3 seconds for VLAN 20:

Switch(config)# spanning-tree vlan 20 hello-time 3

You can verify the previous command by entering the show spanning-tree command in privileged EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree

Enables STP on a VLAN.

spanning-tree port-priority

Configures a port priority, which is used when two switches tie for position as the root switch.

spanning-tree protocol

Specifies the STP protocol to be used for specified spanning-tree instances.

spanning-tree max-age

Use the spanning-tree max-age global configuration command to change the interval between messages the spanning tree receives from the root switch. If a switch does not receive a Bridge Protocol Data Unit (BPDU) message from the root switch within this interval, it recomputes the Spanning Tree Protocol (STP) topology. Use the no form of this command to return to the default interval.

spanning-tree [vlan stp-list] max-age seconds

no spanning-tree [vlan stp-list] max-age

Syntax Description

vlan stp-list

(Optional) List of spanning-tree instances. Each spanning-tree instance is associated with a VLAN ID. Valid IDs are from 1 to 1005. Enter each VLAN ID separated by a space. Do not enter leading zeroes. Ranges are not supported.

seconds

Interval the switch waits between receiving BPDUs from the root switch.
Enter a number from 6 to 200.

Defaults

The default max-age for IEEE STP is 20 seconds. The default for IBM STP is 10 seconds.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

The max-age setting must be greater than the hello-time setting.

If the variable stp-list is omitted, the command applies to the STP instance associated with VLAN 1.

You can set the max-age on a VLAN that has no ports assigned to it. The setting takes effect when you assign ports to the VLAN.

Examples

The following example shows how to set spanning-tree max-age to 30 seconds for VLAN 20:

Switch(config)# spanning-tree vlan 20 max-age 30

The following example shows how to reset the max-age parameter to the default value for spanning-tree instances 100 through 102:

Switch(config)# no spanning-tree vlan 100 101 102 max-age

You can verify the previous commands by entering the show spanning-tree command in privileged EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree forward-time

Sets the forwarding-time for the specified spanning-tree instances.

spanning-tree hello-time

Specifies the interval between hello Bridge Protocol Data Units (BPDUs).

spanning-tree port-priority

Configures a port priority, which is used when two switches tie for position as the root switch.

spanning-tree protocol

Specifies the STP protocol to be used for specified spanning-tree instances.

spanning-tree portfast

Use the spanning-tree portfast interface configuration command to enable the Port Fast feature on a port in all its associated VLANs. When the Port Fast feature is enabled, the port changes directly from a blocking state to a forwarding state without making the intermediate Spanning Tree Protocol (STP) status changes. Use the no form of this command to return the port to default operation.

spanning-tree portfast

no spanning-tree portfast

Syntax Description

This command has no keywords or arguments.

Defaults

The Port Fast feature is disabled; however, it is automatically enabled on dynamic-access ports.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

This feature is not supported on the ATM modules.

This feature should be used only on ports that connect to end stations.

This feature affects all VLANs on the port.

A port with the Port Fast feature enabled is moved directly to the spanning-tree forwarding state.

Examples

The following example shows how to enable the Port Fast feature on fixed port 2.

Switch(config-if)# spanning-tree portfast fa0/2

You can verify the previous commands by entering the show running-config in privilege EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree port-priority

Configures a port priority, which is used when two switches tie for position as the root switch.

spanning-tree port-priority

Use the spanning-tree port-priority interface configuration command to configure a port priority, which is used when two switches tie for position as the root switch. Use the no form of this command to return to the default value.

spanning-tree [vlan stp-list] port-priority port-priority

no spanning-tree [vlan stp-list] port-priority

Syntax Description

vlan stp-list

(Optional) List of spanning-tree instances. Each spanning-tree instance is associated with a VLAN ID. Valid IDs are from 1 to 1005. Enter each VLAN ID separated by a space. Do not enter leading zeroes. Ranges are not supported.

port-priority

Number from 0 to 255. The lower the number, the higher the priority.

Defaults

The default port-priority for IEEE STP and IBM STP is 128.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

If the variable stp-list is omitted, the command applies to the STP instance associated with VLAN 1.

You can set the port priority on a VLAN that has no ports assigned to it. The setting takes effect when you assign ports to the VLAN.

Examples

The following example shows how to increase the likelihood that the spanning-tree instance 20 is chosen as the root switch on port fa0/2:

Switch(config)# interface fa0/2
Switch(config-if)# spanning-tree vlan 20 port-priority 0

You can verify the previous commands by entering the show spanning-tree command in privileged EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree protocol

Specifies the STP protocol to be used for specified spanning-tree instances.

spanning-tree priority

Use the spanning-tree priority global configuration command to configure the switch priority for the specified spanning-tree instance. This changes the likelihood that the switch is selected as the root switch. Use the no form of this command to revert to the default value.

spanning-tree [vlan stp-list] priority bridge-priority

no spanning-tree [vlan stp-list] priority

Syntax Description

vlan stp-list

(Optional) List of spanning-tree instances. Each spanning-tree instance is associated with a VLAN ID. Valid IDs are from 1 to 1005. Enter each VLAN ID separated by a space. Do not enter leading zeroes. Ranges are not supported.

bridge-priority

A number from 0 to 65535. The lower the number, the more likely the switch will be chosen as root.

Defaults

The default bridge priority for IEEE STP and IBM STP is 32768.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

If the variable stp-list is omitted, the command applies to the STP instance associated with VLAN 1.

You can configure the switch priority on a VLAN that has no ports assigned to it. The setting takes effect when you assign ports to the VLAN.

Examples

The following example shows how to set the spanning-tree priority to 125 for a list of VLANs:

Switch(config)# spanning-tree vlan 20 100 101 102 priority 125

You can verify the previous command by entering the show spanning-tree command in privileged EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree forward-time

Sets the forwarding-time for the specified spanning-tree instances.

spanning-tree hello-time

Specifies the interval between hello Bridge Protocol Data Units (BPDUs).

spanning-tree max-age

Changes the interval between messages the spanning tree receives from the root switch.

spanning-tree protocol

Specifies the STP protocol to be used for specified spanning-tree instances.

spanning-tree protocol

Use the spanning-tree protocol global configuration command to specify the Spanning Tree Protocol (STP) to be used for specified spanning-tree instances. Use the no form of this command to use the default protocol.

spanning-tree [vlan stp-list] protocol {ieee | ibm}

no spanning-tree [vlan stp-list] protocol

Defaults

The default protocol is ieee.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

Changing the spanning-tree protocol command causes STP parameters to change to default values of the new protocol.

If the variable stp-list is omitted, this command applies to the STP instance associated with VLAN 1.

You can change the protocol on a VLAN that has no ports assigned to it. The setting takes effect when you assign ports to it.

Examples

The following example shows how to change the STP protocol for VLAN 20 to the IBM version of STP:

Switch(config)# spanning-tree vlan 20 protocol ibm

You can verify the previous command by entering the show spanning-tree command in privileged EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree

Enables STP on a VLAN.

spanning-tree forward-time

Sets the forwarding-time for the specified spanning-tree instances.

spanning-tree max-age

Changes the interval between messages the spanning tree receives from the root switch.

spanning-tree port-priority

Configures a port priority, which is used when two switches tie for position as the root switch.

spanning-tree rootguard

Use the spanning-tree rootguard interface configuration command to enable the root guard feature for all the VLANs associated with the selected port. Root guard restricts which port is allowed to be the Spanning Tree Protocol (STP) root port or the path-to-the root for the switch. The root port provides the best path from the switch to the root switch. Use the no form of this command to disable this feature.

spanning-tree rootguard

no spanning-tree rootguard

Syntax Description

This command has no keywords or arguments.

Defaults

The root guard feature is disabled.

Command Modes

Interface configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

When the root guard feature is enabled, if spanning-tree calculations cause a port to be selected as the root port, the port transitions to the root-inconsistent (blocked) state to prevent the customer's switch from becoming the root switch or being in the path to the root.

When the no spanning-tree rootguard command is executed, the root guard feature is disabled for all VLANs on the selected port. If this port is in the root-inconsistent (blocked) state, the port automatically transitions to the listening state.

Do not enable the root guard on ports that will be used by the UplinkFast feature. With UplinkFast, the backup ports (in the blocked state) replace the root port in the case of a failure. However, if root guard is also enabled, all the backup ports used by the UplinkFast feature are placed in the root-inconsistent state (blocked) and prevented from reaching the forwarding state.

Examples

The following example shows how to enable the root guard feature on all the VLANs associated with interface fa0/3:

Switch(config)# interface fa0/3
Switch(config-if)# spanning-tree rootguard

You can verify the previous commands by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

show running-config

Displays the current operating configuration.

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

spanning-tree cost

Sets the path cost for STP calculations. In the event of a loop, spanning tree considers the path cost when selecting an interface to place into the forwarding state.

spanning-tree port-priority

Configures a port priority, which is used when two switches tie for position as the root switch.

spanning-tree priority

Configures the switch priority for the specified spanning-tree instance and affects the likelihood that the switch is selected as the root switch.

spanning-tree uplinkfast

Use the spanning-tree uplinkfast global configuration command to accelerate the choice of a new root port when a link or switch fails or when Spanning Tree Protocol (STP) reconfigures itself. Use the no form of this command to return to the default value.

spanning-tree uplinkfast [max-update-rate pkts-per-second]

no spanning-tree uplinkfast [max-update-rate pkts-per-second]

Syntax Description

max-update-rate pkts-per-second

The number of packets per second at which stations address update packets are sent. The range is 0 to 1000.

Defaults

UplinkFast is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

When you enable UplinkFast, it is enabled for the entire switch and cannot be enabled for individual VLANs.

When you enable UplinkFast, the bridge priority of all VLANs is set to 49152, and the path cost of all ports and VLAN trunks is increased by 3000. This change reduces the chance that the switch will become the root switch.

When you disable UplinkFast, the bridge priorities of all VLANs and path costs are set to their default values.

Examples

The following command shows how to enable UplinkFast:

Switch(config)# spanning-tree uplinkfast

You can verify the previous command by entering the show spanning-tree command in privileged EXEC mode.

Related Commands

Command Description

show spanning-tree

Displays spanning-tree information for the specified spanning-tree instances.

speed

Use the speed interface configuration command to specify the speed of a Fast Ethernet port. Use the no form of this command to return the port to its default value.

speed {10 | 100 | auto}

no speed

Syntax Description

10

Port runs at 10 Mbps.

100

Port runs at 100 Mbps.

auto

Port automatically detects whether it should run at 10 or 100 Mbps on
Fast Ethernet ports.

Defaults

For Fast Ethernet ports, the default is auto.

For Gigabit Ethernet ports, the speed is 1000 Mbps and is not configurable.

For ATM ports, the speed is 155 Mbps and is not configurable.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA

This command was first introduced.

Usage Guidelines

Certain ports can be configured to be either 10 or 100 Mbps. Applicability of this command is hardware-dependent.

If both the speed and duplex are set to specific values, autonegotiation is disabled.

Note For guidelines on setting the switch speed and duplex parameters, see the Cisco IOS Desktop Switching Software Configuration Guide.

Examples

The following example shows how to set port 1 on module 2 to 100 Mbps:

Switch(config)# interface fastethernet2/1
Switch(config-if)# speed 100

You can verify the previous commands by entering the show running-config in privilege EXEC mode.

Related Commands

Command Description

duplex

Specifies the duplex mode of operation for Fast Ethernet and Gigabit Ethernet ports.

switchport access

Use the switchport access interface configuration command to configure a port as a static-access or dynamic-access port. If the mode is set to access, the port operates as a member of the configured VLAN. If set to dynamic, the port starts discovery of VLAN assignment based on the incoming packets it receives. Use the no form of this command to reset the access mode to the default VLAN for the switch.

switchport access vlan {vlan-id | dynamic}

no switchport access vlan {vlan-id | dynamic}

Syntax Description

vlan vlan-id

ID of the VLAN. Valid IDs are from 1 to 1001. Do not enter leading zeroes.

dynamic

Port is assigned to a VLAN based on the source MAC address of a host (or hosts) connected to that port. The switch sends every new source MAC address received to the VLAN Membership Policy Server (VMPS) to obtain the VLAN name to which the dynamic-access port should be assigned. If the port already has a VLAN assigned and the source has already been approved by the VMPS, the switch forwards the packet to the VLAN.

Defaults

All ports are in static-access mode in VLAN 1.

A dynamic-access port is initially a member of no VLAN and receives its assignment based on the packets it receives.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

11.2(8)SA4

The dynamic keyword was added.

Usage Guidelines

The port must be in access mode before the switchport access vlan vlan-id or switchport access vlan dynamic command can take effect. For more information, see the "switchport mode" section.

An access port can be assigned to only one VLAN.

When the no switchport access vlan form is used, the access mode is reset to static access on VLAN 1.

The following restrictions apply to dynamic-access ports:

The software implements the VLAN Query Protocol (VQP) client, which can query a VMPS such as a Catalyst 5000 series switch. Catalyst 2900 and 3500 XL switches are not VMPS servers. The VMPS server must be configured before a port is configured as dynamic.
Use dynamic-access ports only to connect end stations. Connecting them to switches or routers (that use bridging protocols) can cause a loss of connectivity.
Configure the network so that STP does not put the dynamic-access port into an STP blocking state. The Port Fast feature is automatically enabled on dynamic-access ports.
Dynamic-access ports can only be in one VLAN and do not use VLAN tagging.
Dynamic-access ports cannot be configured as:
- The source or destination port in a static address entry.
- A network port (dynamic-access ports can be assigned to a VLAN in which one of the other ports is a network port).
- A port group (dynamic-access ports cannot be grouped with any other port including other dynamic ports).
- A secure port.
- A port with a secure address.
- A monitor port.

Examples

The following example shows how to assign a port already in access mode to VLAN 2 (instead of the default VLAN 1):

Switch(config-if)# switchport access vlan 2

The following example shows how to assign a port already in access mode to dynamic:

Switch(config-if)# switchport access vlan dynamic

The following example shows how to reconfigure a dynamic-access port to a static-access port:

Switch(config-if)# no switchport access vlan dynamic

You can verify the previous commands by entering the show interface interface-id switchport command in privileged EXEC mode and examining information in the Administrative Mode and Operational Mode rows.

Related Commands

Command Description

switchport mode

Configures the VLAN membership mode of a port.

switchport multi

Configures a list of VLANs to which the port is associated.

switchport mode

Use the switchport mode interface configuration command to configure the VLAN membership mode of a port. Use the no form of this command to reset the mode to the appropriate default for the device.

switchport mode {access | multi | trunk}

no switchport mode {access | multi | trunk}

Syntax Description

access

Set the port to access mode (either static-access or dynamic-access depending on the setting of the switchport access vlan command). The port operates as a nontrunking, single VLAN interface that transmits and receives nonencapsulated frames. An access port can be assigned to only one VLAN.

multi

Set the port to multi-VLAN port mode. The port operates as a nontrunking VLAN interface that transmits and receives nonencapsulated frames. A multi-VLAN port can be assigned to one or more VLANs.

trunk

Set the port to a trunking VLAN Layer-2 interface. The port transmits and receives encapsulated (tagged) frames that identify the VLAN of origination. A trunk is a point-to-point link between two switches or between a switch and a router.

Defaults

All ports are static-access ports in VLAN 1.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

11.2(8)SA4

The trunk keyword was added.

Usage Guidelines

Configuration using the access, multi, or trunk keywords takes effect only when the port is changed to the corresponding mode by using the switchport mode command. The static-access, multi-VLAN, and trunk configurations are saved, but only one configuration is active at a time.

The no switchport mode form resets the mode to static access.

Only these combinations of port modes can appear on a single switch:

Multi-VLAN and access ports
Trunk and access ports

Trunk and multi-VLAN ports cannot coexist on the same switch. If you want to change a multi-VLAN or trunk port into another mode, you must first change it to an access port and then reassign it to the new mode.

Examples

The following example shows how to configure a port for access mode:

Switch(config-if)# switchport mode access

The following example shows how to configure a port for multi-VLAN mode:

Switch(config-if)# switchport mode multi

The following example shows how to configure a port for trunk mode:

Switch(config-if)# switchport mode trunk

Related Commands

Command Description

switchport access

Configures a port as a static-access or dynamic-access port.

switchport multi

Configures a list of VLANs to which the port is associated.

switchport multi

Use the switchport multi interface configuration command to configure a list of VLANs to which the port is associated. If the mode is set to multi, the port operates as a member of all VLANs in the list. Use the no form of this command to reconfigure the port as an access port.

switchport multi vlan {add vlan-list | remove vlan-list}

no switchport multi vlan

Syntax Description

vlan

Indicate the VLAN to which the port is associated.

add vlan-list

List of VLAN IDs to add. Valid IDs are from 1 to 1001. Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Do not enter leading zeroes.

remove vlan-list

List of VLAN IDs to remove. Valid IDs are from 1 to 1001. Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Do not enter leading zeroes.

Defaults

The default for VLAN membership of a multi-VLAN port is VLAN 1.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA3

This command was first introduced.

Usage Guidelines

The switchport mode multi command must be entered before the switchport multi vlan vlan-list command can take effect.

In the variable vlan-list, separate nonconsecutive VLAN IDs with a comma; use a hyphen to designate a range of IDs.

A multi-VLAN port cannot be a secure port or a monitor port.

A multi-VLAN port cannot coexist with a trunk port on the same switch.

Caution To avoid loss of connectivity, do not connect multi-VLAN ports to hubs or switches. Connect multi-VLAN ports to routers or servers.

Examples

The following example shows how to assign a multi-VLAN port already in multimode to two VLANs:

Switch(config-if)# switchport multi vlan 2,4

The following example shows how to assign a multi-VLAN port already in multimode to a range of VLANs:

Switch(config-if)# switchport multi vlan 5-10

The following example shows how to reset the VLAN list of a multi-VLAN port to the default (VLAN 1 only):

Switch(config-if)# no switchport multi vlan

Related Commands

Command Description

switchport access

Configures a port as a static-access or dynamic-access port.

switchport mode

Configures the VLAN membership mode of a port.

switchport priority

Use the switchport priority interface configuration command to set a port priority for the incoming untagged frames or the priority of frames received by the appliance connected to the specified port. Use the no form of this command to return the setting to its default.

switchport priority {default default-priority-id | extend {cos value | none | trust} | override}

no switchport priority {default default-priority-id | extend | override}

Syntax Description

default-priority-id

The priority number for untagged traffic. The priority is a number from
0 to 7. Seven is the highest priority.

extend

Set the 802.1p priority of the appliance.

cos value---Override the 802.1p priority of devices connected to the appliance. The cos value is a number from 0 to 7. Seven is the highest priority. The cos keyword only applies to the 3524-PWR and the 3548 XL switches.

none---The appliance is not instructed what to do with the priority.

trust---Specify that the appliance should trust (honor) the received 802.1p priority from devices connected to it.

override

Override the priority of tagged frames with the default value.

Defaults

The port priority is not set, and the default value for untagged frames received on the port is zero.

The appliance connected to the port is not instructed (none) what to do with the priority.

Command Modes

Interface configuration

Command History

Release Modification

12.0(5)XP

This command was first introduced.

12.0(5)XU

The extend keyword and its options were added.

Usage Guidelines

The default port priority applies if the incoming frame is an untagged frame received from a VLAN trunk or static-access port. This port priority does not apply to the ISL or IEEE 802.1Q VLAN tagged frames. If the incoming frame is an IEEE 802.1Q VLAN tagged frame, the IEEE 802.1p User Priority bits will be used.

The cos keyword only applies to the 3524-PWR and 3548 XL switches.

Examples

The following example shows how to set a default priority on port 3.

Switch(config)# interface fa0/3
Switch(config-if)# switchport priority default 7

All untagged frames received from this port will have the same priority value. You can verify the previous commands by entering the show interface interface-id switchport command in privileged EXEC mode.

The following example shows how to configure the appliance connected to the specified port to honor the received 802.1p priority:

Switch(config-if)# switchport priority extend trust

You can verify the previous command by entering the show interface interface-id switchport command in privileged EXEC mode.

Related Commands

Command Description

power inline

Determines how inline power is applied to the specified port on the 3524-PWR-XL switch.

show interface

Displays the administrative and operational status of a switching (nonrouting) port.

switchport access

Configures a port as a static-access or dynamic-access port.

switchport mode

Configures the VLAN membership mode of a port.

switchport voice vlan

Configures the voice VLAN on the port.

switchport trunk allowed vlan

Use the switchport trunk allowed vlan interface configuration command to control which VLANs can receive and transmit traffic on the trunk. Use the no form of this command to reset the allowed list to the default value.

switchport trunk allowed vlan {add vlan-list | all | except vlan-list | remove vlan-list}

no switchport trunk allowed vlan

Syntax Description

add vlan-list

List of VLAN IDs to add. Valid IDs are from 1 to 1001. Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Do not enter leading zeroes.

all

Add all VLAN IDs to the list.

except vlan-list

List of exception VLAN IDs VLANs are added except the ones specified). Valid IDs are from 1 to 1001. Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Do not enter leading zeroes.

remove vlan-list

List of VLAN IDs to remove. Valid IDs are from 1 to 1001. Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Do not enter leading zeroes.

Defaults

All VLANs are included in the allowed list.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

When the no switchport trunk allowed vlan form is used, the allowed list is reset to the default list, which includes all VLANs.

In the variable vlan-list, separate nonconsecutive VLAN IDs with a comma; use a hyphen to designate a range of IDs. You cannot remove VLAN 1 or 1002 to 1005 from the list.

A trunk port cannot be a secure port or a monitor port. However, a static-access port can monitor a VLAN on a trunk port. The VLAN monitored is the one associated with the static-access port.

If a trunk port is identified as a network port, the trunk port becomes the network port for all the VLANs associated with the port.

Examples

The following example shows how to add VLANs 1, 2, 5, and 6 to the allowed list:

Switch(config-if)# switchport trunk allowed vlan add 1,2,5,6

You can verify the previous command by entering the show interface interface-id switchport command in privileged EXEC mode.

Related Commands

Command Description

switchport mode

Configures the VLAN membership mode of a port.

switchport trunk encapsulation

Sets the encapsulation format on the trunk port.

switchport trunk native

Sets the native VLAN for untagged traffic when in 802.1Q trunking mode.

switchport trunk encapsulation

Use the switchport trunk encapsulation interface configuration command to set the encapsulation format on the trunk port. Use the no form of this command to reset the format to the default.

switchport trunk encapsulation {isl | dot1q}

no switchport trunk encapsulation

Syntax Description

isl

Set the encapsulation format to Inter-Switch Link (ISL). The switch encapsulates all received and transmitted packets with an ISL header. The switch filters native frames received from an ISL trunk port.

dot1q

Set the tagging format to IEEE 802.1Q. With this format, the switch supports simultaneous tagged and untagged traffic on a port.

Defaults

The default encapsulation format is ISL.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

11.2(8)SA5

The dot1q keyword was added.

Usage Guidelines

You cannot configure one end of the trunk as an 802.1Q trunk and the other end as an ISL or nontrunk port. However, you can configure one port as an ISL trunk and another port on the same switch as a 802.1Q trunk.

This command is only applicable on switch platforms and port hardware that support both formats.

Examples

The following example shows how to configure the encapsulation format to 802.1Q:

Switch(config-if)# switchport trunk encapsulation dot1q

You can verify the previous command by entering the show interface interface-id switchport command in privileged EXEC mode.

Related Commands

Command Description

switchport mode

Configures the VLAN membership mode of a port.

switchport trunk allowed vlan

Controls which VLANs can receive and transmit traffic on the trunk.

switchport trunk native

Sets the native VLAN for untagged traffic when in 802.1Q trunking mode.

switchport trunk native

Use the switchport trunk native interface configuration command to set the native VLAN for untagged traffic when in 802.1Q trunking mode. Use the no form of this command to reset the native VLAN to the default.

switchport trunk native vlan vlan-id

no switchport trunk native

Syntax Description

vlan vlan-id

ID of the VLAN that is sending and receiving untagged traffic on the trunk port. Valid IDs are from 1 to 1001. Do not enter leading zeroes.

Defaults

VLAN 1 is the default native VLAN ID on the port.

Command Modes

Interface configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

All untagged traffic received on the 802.1Q trunk port is forwarded with the native VLAN configured for the port.

If a packet has a VLAN ID that is the same as the sending port native VLAN ID, the packet is transmitted untagged; otherwise, the switch transmits the packet with a tag.

Examples

The following example shows how to configure VLAN 3 as the default port to send all untagged traffic:

Switch(config-if)# switchport trunk native vlan 3

You can verify the previous command by entering the show interface interface-id switchport command in privileged EXEC mode.

Related Commands

Command Description

switchport mode

Configures the VLAN membership mode of a port.

switchport trunk allowed vlan

Controls which VLANs can receive and transmit traffic on the trunk.

switchport trunk encapsulation

Sets the encapsulation format on the trunk port.

switchport trunk pruning

Use the switchport trunk pruning interface configuration command to configure the VLAN pruning-eligible list for ports in trunking mode. Use the no form of this command to return the pruning list to the default setting.

switchport trunk pruning vlan {add vlan-list | all | except vlan-list | remove vlan-list}

no switchport trunk pruning

Syntax Description

add vlan-list

List of VLAN IDs to add. Valid IDs are from 2 to 1001. Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Do not enter leading zeroes.

all

Add all VLAN IDs to the list.

except vlan-list

List of exception VLAN IDs (VLANs are added except the specified ones). Valid IDs are from 2 to 1001. Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Do not enter leading zeroes.

remove vlan-list

List of VLAN IDs to remove. Valid IDs are from 2 to 1001. Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Do not enter leading zeroes.

no

Set the pruning list to the default.

Defaults

VLANs 2 through 1001 are pruning eligible.

Command Modes

Interface configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

The pruning-eligible list applies only to trunk ports.

Each trunk port has its own eligibility list.

If you do not want a VLAN to be pruned, remove it from the pruning-eligible list. VLANs that are pruning-ineligible receive flooded traffic.

Examples

The following example shows how to remove VLANs 3 and 10-15 from the pruning-eligible list:

Switch(config-if)# switchport trunk pruning vlan remove 3,10-15

You can verify the previous command by entering the show interface interface-id switchport command in privileged EXEC mode.

Related Commands

Command Description

show interface interface-id pruning

Displays pruning information for the trunk port.

show interface interface-id switchport

Displays the administrative and operational status of a switching (nonrouting) port.

vtp pruning

Enables pruning in the VLAN Trunk Protocol (VTP) administrative domain.

switchport voice vlan

Use the switchport voice vlan interface configuration command to configure the voice VLAN on the port. Use the no form of this command to return the setting to its default.

switchport voice vlan {vlan-id | dot1p | none | untagged}

no switchport voice vlan

Syntax Description

vlan-id

VLAN used for voice traffic. Valid IDs are from 1 to 1001 (IDs 1002 to 4094 are not supported on Catalyst 2900 and 3500 XL switches).
Do not enter leading zeroes. The switch port is an 802.1Q trunk port.

dot1p

The telephone uses priority tagging and uses VLAN 0 (the native VLAN). The switch port is an 802.1Q trunk port.

none

The telephone is not instructed through the CLI about the voice VLAN. The telephone uses the configuration from the telephone key pad.

untagged

The telephone does not tag frames and uses VLAN 4095. The switch port can be an access port or an 802.1Q trunk port.

Defaults

The switch default is not to automatically configure the telephone (none).

The telephone default is not to tag frames.

Command Modes

Interface configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

Ports that are not configured as trunk ports but have a configured voice VLAN are access ports with a voice VLAN ID (VVID).

Examples

The following example shows how to configure VLAN 2 as the voice VLAN:

Switch(config-if)# switchport voice vlan 2

You can verify the previous command by entering the show interface interface-id switchport command in privileged EXEC mode.

Related Commands

Command Description

power inline

Determines how inline power is applied to the specified port on the 3524-PWR-XL switch.

show interface interface-id switchport

Displays the administrative and operational status of a switching (nonrouting) port.

switchport priority extend

Determines how the appliance connected to the specified port handles priority traffic received on its incoming port.

tacacs-server attempts

Use the tacacs-server attempts global configuration command to control the number of login attempts that can be made on a line set up for Terminal Access Controller Access Control System (TACACS), Extended TACACS, or TACACS+ verification. Use the no form of this command to disable this feature and restore the default.

tacacs-server attempts count

no tacacs-server attempts

Syntax Description

count

Integer that sets the number of attempts. The range is from 1 to 1000.

Defaults

The default number of login attempts is 3.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Examples

The following example shows how to change the login attempt to just one:

Switch(config)# tacacs-server attempts 1

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

enable use-tacacs

Enables the use of TACACS to determine whether a user can access the privileged command level.

login tacacs

Configures the switch to use TACACS user authentication.

show tacacs

Displays various TACACS+ server statistics.

tacacs-server directed-request

Sends only a username to a specified server when a direct request is issued in association with TACACS, Extended TACACS, and TACACS+.

tacacs-server host

Specifies a TACACS, Extended TACACS, or TACACS+ host.

tacacs-server key

Sets the authentication encryption key used for all TACACS+ communications between the access server and the TACACS+ daemon.

tacacs-server last-resort

Causes the network access server to request the privileged password as verification for TACACS or Extended TACACS or to allow successful login without further user input.

tacacs-server timeout

Sets the interval that the server waits for a TACACS, Extended TACACS, or TACACS+ server to reply.

tacacs-server directed-request

Use the tacacs-server directed-request global configuration command to send only a username to a specified server when a direct request is issued in association with Terminal Access Controller Access Control System (TACACS), Extended TACACS, and TACACS+. Use the no form of this command to send the whole string, both before and after the @ symbol.

tacacs-server directed-request

no tacacs-server directed-request

Syntax Description

This command has no arguments or keywords.

Defaults

The directed-request feature is enabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

This command sends only the portion of the username before the @ symbol to the host specified after the @ symbol. In other words, with the directed-request feature enabled, you can direct a request to any of the configured servers, and only the username is sent to the specified server.

Using no tacacs-server directed-request causes the whole string, both before and after the @ symbol, to be sent to the default TACACS server. When the directed-request feature is disabled, the router queries the list of servers, starting with the first one in the list. It sends the whole string and accepts the first response it gets from the server. The tacacs-server directed-request command is useful for sites that have developed their own TACACS server software that parses the whole string and makes decisions based on it.

With tacacs-server directed-request enabled, only configured TACACS servers can be specified by the user after the @ symbol. If the host name specified by the user does not match the IP address of a TACACS server configured by the administrator, the user input is rejected.

Use no tacacs-server directed-request to disable the ability of the user to choose between configured TACACS servers and to cause the entire string to be passed to the default server.

Examples

The following example shows how to pass the entire user input to the default TACACS server:

Switch(config)# no tacacs-server directed-request

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

tacacs-server dns-alias-lookup

Use the tacacs-server dns-alias-lookup global configuration command to enable IP Domain Name System alias lookup for Terminal Access Controller Access Control System Plus (TACACS+). Use the no form of this command to disable this feature.

tacacs-server dns-alias-lookup

no tacacs-server dns-alias-lookup

Syntax Description

This command has no keywords or arguments.

Defaults

The DNS alias lookup is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Examples

The following example shows how to enable the IP DNS alias lookup:

Switch(config)# tacacs-server dns-alias-lookup

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

ip domain-name

Defines a default domain name that is used to complete unqualified host names (names without a dotted-decimal domain name).

ip name-server

Specifies the address of one or more name servers to use for name and address resolution.

tacacs-server extended

Use the tacacs-server extended global configuration command to enable an Extended Terminal Access Controller Access Control System (TACACS) mode. Use the no form of this command to disable the mode.

tacacs-server extended

no tacacs-server extended

Syntax Description

This command has no arguments or keywords.

Defaults

The Extended TACACS mode is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

This command initializes Extended TACACS. To initialize authentication, authorization, and accounting (AAA) and TACACS+, use the aaa new-model command.

Examples

The following example shows how to enable Extended TACACS mode:

Switch(config)# tacacs-server extended

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

tacacs-server host

Use the tacacs-server host global configuration command to specify a Terminal Access Controller Access Control System (TACACS), Extended TACACS, or TACACS+ host. Use the no form of this command to delete the specified name or address.

tacacs-server host hostname [single-connection] [port integer] [timeout integer] [key string]

no tacacs-server host hostname

Syntax Description

hostname

Name or IP address of the host.

single-connection

(Optional) Specify that the switch maintain a single open connection for confirmation from an authentication, authorization, and accounting (AAA) and TACACS+ server (CiscoSecure Release 1.0.1 or later). This command contains no autodetect and fails if the specified host is not running a CiscoSecure daemon.

port integer

(Optional) Specify a server port number. The range is from 1 to 65535.

timeout integer

(Optional) Specify a timeout value. This overrides the global timeout value set with the tacacs-server timeout command for this server only. The timeout is an integer in seconds.The range is from 1 to 300 seconds.

key string

(Optional) Specify an authentication and encryption key. This key must match the key used by the TACACS+ daemon. Specifying this key overrides the key set by the global configuration tacacs-server key command for this server only. The key string is a character string specifying the authentication and encryption key.

Defaults

No host is specified.

The default port number is 49.

The default timeout is 5 seconds.

No key string is specified.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

You can use multiple tacacs-server host commands to specify additional hosts. The Cisco IOS software searches for hosts in the order in which you specify them. Use the single-connection, port, timeout, and key options only when running an AAA/TACACS+ server.

Because some of the parameters of the tacacs-server host command override global settings made by the tacacs-server timeout and tacacs-server key commands, you can use this command to enhance security on your network by uniquely configuring individual switches.

Examples

The following example shows how to specify a TACACS host named Sea_Change:

Switch(config)# tacacs-server host Sea_Change

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

The following example shows how to specify that the switch consult the CiscoSecure TACACS+ host named Sea_Cure on port number 51 for AAA confirmation. The timeout value for requests on this connection is 3 seconds; the encryption key is a_secret.

Switch(config)# tacacs-server host Sea_Cure single-connection port 51 timeout 3 key a_secret

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

login tacacs

Configures the switch to use TACACS user authentication.

tacacs-server key

Sets the authentication encryption key used for all TACACS+ communications between the access server and the TACACS+ daemon.

tacacs-server timeout

Sets the interval that the server waits for a TACACS, Extended TACACS, or TACACS+ server to reply.

tacacs-server key

Use the tacacs-server key global configuration command to set the authentication encryption key used for all Terminal Access Controller Access Control System Plus (TACACS+) communications between the access server and the TACACS+ daemon. Use the no form of the command to disable the key.

tacacs-server key key

no tacacs-server key [key]

Syntax Description

key

Key used to set authentication and encryption. This key must match the key used on the TACACS+ daemon.

Defaults

No key is specified.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

After enabling authentication, authorization, and accounting (AAA) with the aaa new-model command, you must set the authentication and encryption key by using the tacacs-server key command.

The key entered must match the key used on the TACACS+ daemon. All leading spaces are ignored; spaces within and at the end of the key are not. If you use spaces in your key, do not enclose the key in quotation marks unless the quotation marks themselves are part of the key.

Examples

The following example shows how to set the authentication and encryption key to dare to go:

Switch(config)# tacacs-server key dare to go

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

aaa new-model

Enables the AAA access control model.

tacacs-server host

Specifies a TACACS, Extended TACACS, or TACACS+ host.

tacacs-server last-resort

Use the tacacs-server last-resort global configuration command to cause the network access server to request the privileged password as verification for Terminal Access Controller Access Control System (TACACS) or Extended TACACS or to allow successful log in without further user input. Use the no form of the command to restore the system to the default behavior.

tacacs-server last-resort {password | succeed}

no tacacs-server last-resort {password | succeed}

Syntax Description

password

Provide the user access to the privileged EXEC command mode by entering the password set by the enable command.

succeed

Provide the user access to the privileged EXEC command mode without further question.

Defaults

The last-resort feature is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Use the tacacs-server last-resort command to be sure that you can log in; for example, a systems administrator would use this command to log in to troubleshoot TACACS servers that might be down.

Note This command is not used in authentication, authorization, and accounting (AAA) and TACACS+.

Examples

The following example shows how to force successful log in:

Switch(config)# tacacs-server last-resort succeed

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

enable password

Sets a local password to control access to various privilege levels.

login (EXEC)

Changes a login username.

tacacs-server login-timeout

Use the tacacs-server login-timeout global configuration command to cause the network access server to request the privileged password as verification for Terminal Access Controller Access Control System (TACACS) or Extended TACACS or to allow successful log in without further user input. Use the no form of the command to restore the system to the default behavior.

tacacs-server login-timeout {password | succeed}

no tacacs-server login-timeout {password | succeed}

Syntax Description

password

Provide the user access to the privileged EXEC command mode by entering the password set by the enable command.

succeed

Provide the user access to the privileged EXEC command mode without further question.

s

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

Use the tacacs-server login-timeout command to be sure that you can log in; for example, a system administrator would use this command to log in to troubleshoot TACACS servers that might be down.

Note This command is not used in authentication, authorization, and accounting (AAA)/TACACS+.

Examples

The following example shows how to force successful log in:

Switch(config)# tacacs-server login-timeout succeed

Related Commands

Command Description

enable password

Sets a local password to control access to various privilege levels.

login (EXEC)

Changes a login username.

tacacs-server optional-passwords

Use the tacacs-server optional-passwords global configuration command to specify that the first Terminal Access Controller Access Control System (TACACS) request to a TACACS or Extended TACACS server be made without password verification. Use the no form of this command to restore the default.

tacacs-server optional-passwords

no tacacs-server optional-passwords

Syntax Description

This command has no arguments or keywords.

Defaults

Password verification is disabled.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

When the user enters the login name, the login request is transmitted with the name and a zero-length password. If accepted, the login procedure completes. If the TACACS server refuses this request, the server software prompts for a password and tries again when the user supplies a password. The TACACS server must support authentication for users without passwords to make use of this feature. This feature supports all TACACS request---login, Serial Line Internet Protocol (SLIP), enable, and so on.

Note This command is not used in authentication, authorization, and accounting (AAA)/TACACS+.

Examples

The following example shows how to configure the first login to bypass TACACS verification:

Switch(config)# tacacs-server optional-passwords

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

tacacs-server retransmit

Use the tacacs-server retransmit global configuration command to specify the number of times the Cisco IOS software searches the list of Terminal Access Controller Access Control System (TACACS) or Extended TACACS server hosts. Use the no form of this command to disable retransmission.

tacacs-server retransmit retries

no tacacs-server retransmit

Syntax Description

retries

Integer that specifies the retransmit count. The range is from 0 to 100.

Defaults

The default is two retries.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Usage Guidelines

The Cisco IOS software tries all servers, allowing each one to time out before increasing the retransmit count.

Examples

The following example shows how to specify a retransmit counter value of 5:

Switch(config)# tacacs-server retransmit 5

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

tacacs-server timeout

Use the tacacs-server timeout global configuration command to set the interval that the server waits for a Terminal Access Controller Access Control System (TACACS), Extended TACACS, or TACACS+ server to reply. Use the no form of this command to restore the default.

tacacs-server timeout seconds

no tacacs-server timeout

Syntax Description

seconds

Integer that specifies the timeout interval in seconds. The range is from 1 to 1000.

Defaults

The timeout interval is 5 seconds.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA6

This command was first introduced.

Examples

The following example shows how to change the interval timer to 10 seconds:

Switch(config)# tacacs-server timeout 10

You can verify the previous command by entering the show running-config command in privileged EXEC mode.

Related Commands

Command Description

tacacs-server host

Specifies a TACACS, Extended TACACS, or TACACS+ host.

udld

Use the udld interface configuration command to enable UniDirectional Link Detection (UDLD) on a port to assist with the detection of spanning-tree loops on logical one-way connections. Use the no form of this command to return the port setting to the global setting.

udld {enable | disable}

no udld {enable | disable}

Syntax Description

enable

Enable UDLD on the specified port.

disable

Disable UDLD on the specified port.

Defaults

UDLD follows the setting of the udld enable global configuration command and is disabled on all ports.

Command Modes

Interface configuration

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

UDLD is supported on fiber- and copper-based Ethernet ports.

UDLD is not supported on ATM interfaces.

A UDLD-capable port cannot detect a unidirectional link if it is connected to a UDLD-incapable port of another switch.

This setting overrides the global UDLD configuration on the switch.

Examples

The following example shows how to enable UDLD on port 2:

Switch(config)# interface fastethernet 0/2
Switch(config-if)# udld enable

You can verify the previous command by entering the show running-config or the show udld interface command in privilege EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

show udld

Displays UDLD status for all ports or the specified port.

udld enable

Enables UDLD on all ports on the switch.

udld reset

Resets any interface that has been shut down by UDLD.

udld enable

Use the udld enable global configuration command to enable UniDirectional Link Detection (UDLD) on all ports on the switch to assist with the detection of spanning-tree loops on logical one-way connections. Use the no form of this command to return the switch setting to its default value.

udld enable

no udld enable

Syntax Description

This command has no keywords or arguments.

Defaults

UDLD is disabled on the switch.

Command Modes

Global configuration mode

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Usage Guidelines

UDLD is supported on fiber- and copper-based Ethernet ports.

UDLD is not supported on ATM interfaces.

A UDLD-capable port cannot detect a unidirectional link if it is connected to a UDLD-incapable port of another switch.

This setting is overridden by each specific port UDLD configuration.

Examples

The following example shows how to enable UDLD on the switch:

Switch(config)# udld enable

You can verify the previous command by entering the show running-config in privilege EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

show udld

Displays UDLD status for all ports or the specified port.

udld

Enables UDLD on a port.

udld reset

Resets any interface that has been shut down by UDLD.

udld reset

Use the udld reset privileged EXEC command to reset all interfaces that have been shut down by UniDirectional Link Detection (UDLD).

udld reset

Syntax Description

This command has no keywords or arguments.

Command Modes

Privileged EXEC mode

Command History

Release Modification

12.0(5)XU

This command was first introduced.

Examples

The following example shows how to reset all interfaces that have been shut down by UDLD:

Switch# udld reset
1 ports shutdown by UDLD were reset.

You can verify the previous command by entering the show udld in user EXEC mode.

Related Commands

Command Description

show running-config

Displays the running configuration on the switch.

show udld

Displays UDLD status for all ports or the specified port.

udld

Enables UDLD on a port.

udld enable

Enables UDLD on all ports on the switch.

vlan

Use the vlan VLAN database command to configure VLAN characteristics. Use the no form of this command to delete a VLAN and its configured characteristics.

vlan vlan-id [name vlan-name] [media {ethernet | fddi | fdi-net | tokenring | tr-net}]
[state {suspend | active}] [said said-value] [mtu mtu-size] [ring ring-number]
[bridge bridge-number | type {srb | srt}] [parent parent-vlan-id]
[stp type {ieee | ibm | auto}] [are are-number] [ste ste-number]
[backupcrf {enable | disable}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

no vlan vlan-id [name vlan-name] [media {ethernet | fddi | fdi-net | tokenring | tr-net}]
[state {suspend | active}] [said said-value] [mtu mtu-size] [ring ring-number]
[bridge bridge-number | type {srb | srt}] [parent parent-vlan-id]
[stp type {ieee | ibm | auto}] [are are-number] [ste ste-number]
[backupcrf {enable | disable}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

Note Catalyst 2900 and 3500 XL switches support only Ethernet ports. You configure only FDDI and Token Ring media-specific characteristics for VLAN Trunk Protocol (VTP) global advertisements to other switches. These VLANs are locally suspended.

Table 2-8 lists the valid syntax for each media type.

Table 2-8: Valid Syntax for Different Media Types

Media Type Valid Syntax

Ethernet

vlan vlan-id [name vlan-name] media ethernet [state {suspend | active}]
[said said-value] [mtu mtu-size] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

FDDI

vlan vlan-id [name vlan-name] media fddi [state {suspend | active}]
[said said-value] [mtu mtu-size] [ring ring-number] [parent parent-vlan-id] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

FDDI-NET

vlan vlan-id [name vlan-name] media fdi-net [state {suspend | active}]
[said said-value] [mtu mtu-size] [bridge bridge-number]
[stp type {ieee | ibm | auto}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

If VTP V2 mode is disabled, do not set the stp type to auto.

Token Ring

VTP V2 mode is disabled.

vlan vlan-id [name vlan-name] media tokenring [state {suspend | active}]
[said said-value] [mtu mtu-size] [ring ring-number] [parent parent-vlan-id]
[tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

Token Ring concentrator relay function (TRCRF)

VTP V2 mode is enabled.

vlan vlan-id [name vlan-name] media tokenring [state {suspend | active}]
[said said-value] [mtu mtu-size] [ring ring-number] [parent parent-vlan-id]
[bridge type {srb | srt}] [are are-number] [ste ste-number]
[backupcrf {enable | disable}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

Token Ring-NET

VTP V2 mode is disabled.

vlan vlan-id [name vlan-name] media tr-net [state {suspend | active}]
[said said-value] [mtu mtu-size] [bridge bridge-number]
[stp type {ieee | ibm}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

Token Ring bridge relay function (TRBRF)

VTP V2 mode is enabled.

vlan vlan-id [name vlan-name] media tr-net [state {suspend | active}]
[said said-value] [mtu mtu-size] [bridge bridge-number]
[stp type {ieee | ibm | auto}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]

VLAN Configuration Rules

Table 2-9 describes the rules for configuring VLANs.

Table 2-9: VLAN Configuration Rules

Configuration Rule

VTP V2 mode is enabled, and you are configuring a TRCRF VLAN media type.

Specify a parent VLAN ID of a TRBRF that already exists in the database.

Specify a ring number. Do not leave this field blank.

Specify unique ring numbers when TRCRF VLANs have the same parent VLAN ID. Only one backup concentrator relay function (CRF) can be enabled.

VTP V2 mode is enabled, and you are configuring VLANs other than TRCRF media type.

Do not specify a backup CRF.

VTP V2 mode is enabled, and you are configuring a TRBRF VLAN media type.

Specify a bridge number. Do not leave this field blank.

VTP V2 mode is disabled.

No VLAN can have an STP type set to auto.

This rule applies to Ethernet, FDDI, FDDI-NET, Token Ring, and Token Ring-NET VLANs.

Add a VLAN that requires translational bridging (values are not set to zero).

The translational bridging VLAN IDs that are used must already exist in the database.

The translational bridging VLAN IDs that a configuration points to must also contain a pointer to the original VLAN in one of the translational bridging parameters (for example, Ethernet points to FDDI, and FDDI points to Ethernet).

The translational bridging VLAN IDs that a configuration points to must be different media types than the original VLAN (for example, Ethernet can point to Token Ring).

If both translational bridging VLAN IDs are configured, these VLANs must be different media types (for example, Ethernet can point to FDDI and Token Ring).

Syntax Description

vlan-id

ID of the configured VLAN. Valid IDs are from 1 to 1005 and must be unique within the administrative domain. Do not enter leading zeroes.

name

(Optional) Keyword to be followed by the VLAN name.

vlan-name

ASCII string from 1 to 32 characters that must be unique within the administrative domain.

media

(Optional) Keyword to be followed by the VLAN media type.

ethernet

Ethernet media type.

fddi

FDDI media type.

fdi-net

FDDI network entity title (NET) media type.

tokenring

Token Ring media type if the VTP V2 mode is disabled.

TRCRF media type if the VTP V2 mode is enabled.

tr-net

Token Ring network entity title (NET) media type if the VTP V2 mode is disabled.

TRBRF media type if the VTP V2 mode is enabled.

state

(Optional) Keyword to be followed by the VLAN state.

active

VLAN is operational.

suspend

VLAN is suspended. Suspended VLANs do not pass packets.

said

(Optional) Keyword to be followed by the security association identifier (SAID) as documented in IEEE 802.10.

said-value

Integer from 1 to 4294967294 that must be unique within the administrative domain.

mtu

(Optional) Keyword to be followed by the maximum transmission unit (packet size in bytes).

mtu-size

Packet size in bytes from 1500 to 18190 that the VLAN can use.

ring

(Optional) Keyword to be followed by the logical ring for an FDDI, Token Ring, or TRCRF VLAN.

ring-number

Integer from 1 to 4095.

bridge

(Optional) Keyword to be followed by the logical distributed source-routing bridge. This bridge that interconnects all logical rings having this VLAN as a parent VLAN in FDDI-NET, Token Ring-NET, and TRBRF VLANs.

bridge-number

Integer from 0 to 15.

type

Keyword to be followed by the bridge type. Applies only to TRCRF VLANs.

srb

Source-route bridging VLAN.

srt

Source-route transparent bridging VLAN.

parent

(Optional) Keyword to be followed by the parent VLAN of an existing FDDI, Token Ring, or TRCRF VLAN. This parameter identifies the TRBRF to which a TRCRF belongs and is required when defining a TRCRF.

parent-vlan-id

Integer from 0 to 1005.

stp type

(Optional) Keyword to be followed by the spanning-tree type for FDDI-NET, Token Ring-NET, or TRBRF VLAN.

ieee

IEEE Ethernet STP running source-route transparent (SRT) bridging.

ibm

IBM STP running source-route bridging (SRB).

auto

STP running a combination of source-route transparent bridging (IEEE) and source-route bridging (IBM).

are

Keyword to be followed by the number of all-routes explorer (ARE) hops. This keyword applies only to TRCRF VLANs.

are-number

Integer from 0 to 13 that defines the maximum number of ARE hops for this VLAN.

ste

Keyword to be followed by the number of spanning-tree explorer (STE) hops. This keyword applies only to TRCRF VLANs.

ste-number

Integer from 0 to 13 that defines the maximum number of STE hops for this VLAN.

backupcrf

Keyword to be followed by the backup CRF mode. This keyword applies only to TRCRF VLANs.

enable

Enable backup CRF mode for this VLAN.

disable

Disable backup CRF mode for this VLAN.

tb-vlan1 and tb-vlan2

(Optional) Keyword to be followed by the first and second VLAN to which this VLAN is translationally bridged. Translational VLANs translate FDDI or Token Ring to Ethernet, for example.

tb-vlan1-id and tb-vlan2-id

Integer that ranges from 0 to 1005.

Defaults

The vlan-name variable is VLANxxxx, where xxxx represents four numeric digits (including leading zeroes) equal to the VLAN ID number.

The media type is ethernet.

The state is active.

The said value is 100000 plus the VLAN ID.

The mtu size for Ethernet, FDDI, and FDDI-NET VLANs is 1500 bytes. The MTU size for Token Ring and Token Ring-NET VLANs is 1500 bytes. The MTU size for TRBRF and TRCRF VLANs is 4472 bytes.

The ring number for Token Ring VLANs is zero. For FDDI VLANs, there is no default. For TRCRF VLANs, you must specify a ring number.

The bridge number is zero (no source-routing bridge) for FDDI-NET and Token Ring-NET VLANs. For TRBRF VLANs, you must specify a bridge number.

The parent VLAN ID is zero (no parent VLAN) for FDDI and Token Ring VLANs. For TRCRF VLANs, you must specify a parent VLAN ID. For both Token Ring and TRCRF VLANs, the parent VLAN ID must already exist in the database and be associated with a Token Ring-NET or TRBRF VLAN.

The STP type is ieee for FDDI-NET VLANs. For Token Ring-NET and TRBRF VLANs, the default is ibm.

The ARE value is 7.

The STE value is 7.

Backup CRF is disabled.

The tb-vlan1-id and tb-vlan2-id variables are zero (no translational bridging).

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

When the no vlan vlan-id form is used, the VLAN is deleted. Deleting VLANs automatically resets to zero any other parent VLANs and translational bridging parameters that refer to the deleted VLAN.

When the no vlan vlan-id name vlan-name form is used, the VLAN name returns to the default name (VLANxxxx, where xxxx represent four numeric digits (including leading zeroes) equal to the VLAN ID number).

When the no vlan vlan-id media form is used, the media type returns to the default (ethernet). Changing the VLAN media type (including the no form) resets the VLAN MTU to the default MTU for the type (unless the mtu keyword is also present in the command). It also resets the VLAN parent and translational bridging VLAN to the default (unless the parent, tb-vlan1, and/or tb-vlan2 are also present in the command).

When the no vlan vlan-id state form is used, the VLAN state returns to the default (active).

When the no vlan vlan-id said form is used, the VLAN SAID returns to the default (100,000 plus the VLAN ID).

When the no vlan vlan-id mtu form is used, the VLAN MTU returns to the default for the applicable VLAN media type. You can also modify the MTU using the media keyword.

When the no vlan vlan-id ring form is used, the VLAN logical ring number returns to the default (0).

When the no vlan vlan-id bridge form is used, the VLAN source-routing bridge number returns to the default (0). The vlan vlan-id bridge command is only used for FDDI-NET and Token Ring-NET VLANs and is ignored in other VLAN types.

When the no vlan vlan-id parent form is used, the parent VLAN returns to the default (0). The parent VLAN resets to the default if the parent VLAN is deleted or if the media keyword changes the VLAN type or the VLAN type of the parent VLAN.

When the no vlan vlan-id stp type form is used, the VLAN spanning-tree type returns to the default (ieee).

When the no vlan vlan-id tb-vlan1 or no vlan vlan-id tb-vlan2 form is used, the VLAN translational bridge VLAN (or VLANs, if applicable) returns to the default (0). Translational bridge VLANs must be a different VLAN type than the affected VLAN, and if two are specified, the two must be different VLAN types from each other. A translational bridge VLAN resets to the default if the translational bridge VLAN is deleted, if the media keyword changes the VLAN type, or if the media keyword changes the VLAN type of the corresponding translation bridge VLAN.

Examples

The following example shows how to add an Ethernet VLAN with default media characteristics. The default includes a vlan-name of VLANxxx, where xxxx represents four numeric digits (including leading zeroes) equal to the VLAN ID number. The default media option is ethernet; the state option is active. The default said-value variable is 100000 plus the VLAN ID; the mtu-size variable is 1500; the stp-type option is ieee. The VLAN is added if it did not already exist; otherwise, this command does nothing.

Switch(vlan)# vlan 2

The following example shows how to modify an existing VLAN by changing its name and MTU size:

Switch(vlan)# no vlan name engineering mtu 1200

You can verify the previous commands by entering the show vlan command in privileged EXEC mode.

Related Commands

Command Description

show vlan

Displays the parameters for all configured VLANs or one VLAN (if the VLAN ID or name is specified) in the administrative domain.

vlan database

Use the vlan database privileged EXEC command to enter VLAN database mode from the command-line interface (CLI). From the CLI, you can add, delete, and modify VLAN configurations and globally propagate these changes by using the VLAN Trunk Protocol (VTP).

vlan database

Syntax Description

This command has no arguments or keywords.

Defaults

No default is defined.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

To return to the privileged EXEC mode from the VLAN database mode, enter the exit command.

Note This command mode is different from other modes because it is session-oriented. When you add, delete, or modify VLAN parameters, the changes are not applied until you exit the session by entering the apply or exit commands. When the changes are applied, the VTP configuration version is incremented. You can also not apply the changes to the VTP database by entering abort.

Examples

The following example shows how to enter the VLAN database mode from the privileged EXEC mode:

Switch# vlan database
Switch(vlan)#

Related Commands

Command Description

abort

Abandons the proposed new VLAN database, exits VLAN database mode, and returns to privileged EXEC mode.

apply

Implements the proposed new VLAN database, increments the database configuration revision number, propagates it throughout the administrative domain, and remains in VLAN database mode.

reset

Abandons the proposed VLAN database and remains in VLAN database mode. Resets the proposed database to the currently implemented VLAN database on the switch.

shutdown vlan

Shuts down (suspends) local traffic on the specified VLAN.

vmps reconfirm (Privileged EXEC)

Use the vmps reconfirm privileged EXEC command to immediately send VLAN Query Protocol (VQP) queries to reconfirm all dynamic VLAN assignments with the VLAN Membership Policy Server (VMPS).

vmps reconfirm

Syntax Description

This command has no arguments or keywords.

Defaults

No default is defined.

Command Modes

Privileged EXEC

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

The following example shows how to immediately send VQP queries to the VMPS:

Switch# vmps reconfirm

You can verify the previous command by entering the show vmps command in privileged EXEC mode and examining the VMPS Action row of the Reconfirmation Status section. The show vmps command shows the result of the last time the assignments were reconfirmed either as a result of reconfirmation timer expiring or because the vmps reconfirm command was issued.

Related Commands

Command Description

show vmps

Displays VQP and VMPS information.

vmps reconfirm

Sends VQP queries to reconfirm all dynamic VLAN assignments with the VMPS.

vmps reconfirm (Global Configuration)

Use the vmps reconfirm global configuration command to change the reconfirmation interval for the VLAN Query Protocol (VQP) client.

vmps reconfirm interval

Syntax Description

interval

Reconfirmation interval for VQP client queries to the VLAN Membership Policy Server (VMPS) to reconfirm dynamic VLAN assignments. The interval range is from 1 to 120 minutes.

Defaults

The default reconfirmation interval is 60 minutes.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

The following example shows how to set the VQP client to reconfirm dynamic VLAN entries every 20 minutes:

Switch(config)# vmps reconfirm 20

You can verify the previous command by entering the show vmps command in privileged EXEC mode and examining information in the Reconfirm Interval row.

Related Commands

Command Description

show vmps

Displays VQP and VMPS information.

vmps reconfirm

Sends VQP queries to reconfirm all dynamic VLAN assignments with the VMPS.

vmps retry

Use the vmps retry global configuration command to configure the per-server retry count for the VLAN Query Protocol (VQP) client.

vmps retry count

Syntax Description

count

Number of attempts to contact the VLAN Membership Policy Server (VMPS) by the client before querying the next server in the list. The retry range is from 1 to 10.

Defaults

The default retry count is 3.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Examples

The following example shows how to set the retry count to 7:

Switch(config)# vmps retry 7

You can verify the previous command by entering the show vmps command in privileged EXEC mode and examining information in the Server Retry Count row.

Related Commands

Command Description

show vmps

Displays VQP and VMPS information.

vmps server

Use the vmps server global configuration command to configure the primary VLAN Membership Policy Server (VMPS) and up to three secondary servers. Use the no form of this command to remove a VMPS server.

vmps server ipaddress [primary]

no vmps server [ipaddress]

Syntax Description

ipaddress

IP address or host name of the primary or secondary VMPS servers. If you specify a host name, the Domain Name System (DNS) server must be configured.

primary

(Optional) Determines whether primary or secondary VMPS servers are being configured.

Defaults

No primary or secondary VMPS servers are defined.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

The first server entered is automatically selected as the primary server whether or not primary is entered. The first server address can be overridden by using primary in a subsequent command.

If a member switch in a cluster configuration does not have an IP address, the cluster does not use the VMPS server configured for that member switch. Instead, the cluster uses the VMPS server on the command switch, and the command switch proxies the VMPS requests. The VMPS server treats the cluster as a single switch and uses the IP address of the command switch to respond to requests.

When using the no form without specifying the ipaddress, all configured servers are deleted. If you delete all servers when dynamic-access ports are present, the switch cannot forward packets from new sources on these ports because it cannot query the VMPS.

Examples

The following example shows how to configure the server with IP address 191.10.49.20 as the primary VMPS server. The servers with IP addresses 191.10.49.21 and 191.10.49.22 are configured as secondary servers:

Switch(config)# vmps server 191.10.49.20 primary
Switch(config)# vmps server 191.10.49.21
Switch(config)# vmps server 191.10.49.22

The following example shows how to delete the server with IP address 191.10.49.21:

Switch(config)# no vmps server 191.10.49.21

You can verify the previous commands by entering the show vmps command in privileged EXEC mode and examining information in the VMPS Domain Server row.

Related Commands

Command Description

show vmps

Displays VQP and VMPS information.

vtp

Use the vtp VLAN database command to configure the VLAN Trunk Protocol (VTP) mode. Use the no form of this command to return to the default setting.

vtp {server | client | transparent}

no vtp {server | client | transparent}

Syntax Description

server

Place the switch in VTP server mode. A switch in VTP server mode is enabled for VTP and sends advertisements. You can configure VLANs on it. The switch can recover all the VLAN information in the current VTP database from nonvolatile storage after reboot.

client

Place the switch in VTP client mode. A switch in VTP client mode is enabled for VTP, can send advertisements, but does not have enough nonvolatile storage to store VLAN configurations. You cannot configure VLANs on it. When a VTP client starts up, it does not transmit VTP advertisements until it receives advertisements to initialize its VLAN database.

transparent

Place the switch in VTP transparent mode. A switch in VTP transparent mode is disabled for VTP, does not transmit advertisements or learn from advertisements sent by other devices, and cannot affect VLAN configurations on other devices in the network. The switch receives VTP advertisements and forwards them on all trunk ports except the one on which the advertisement was received. The configuration of multi-VLAN ports causes the switch to automatically enter transparent mode.

Note The switch supports up to 250 VLANs on the Catalyst 2912MF, 2924M, and 3500 XL switches. All other 2900 XL switches support up to 64 VLANs. If you define more than 250 or 64, respectively, or if the switch receives an advertisement that contains more than 250 or 64 VLANs, the switch automatically enters VTP transparent mode and operates with the VLAN configuration preceding the one that put it into transparent mode. The count of 250 or 64 VLANs always includes VLAN 1 but never includes VLANs 1002 to 1005. The switch can have 250 or 64 active VLANs, plus VLANs 1002 through 1005, which are inactive.

Defaults

Server mode is the default mode.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

The no vtp client and no vtp transparent forms of the command return the switch to VTP server mode.

The vtp server command is the same as no vtp client or no vtp transparent except that it does not return an error if the switch is not in client or transparent mode.

Examples

The following example shows how to place the switch in VTP transparent mode:

Switch(vlan)# vtp transparent

You can verify the previous commands by entering the show vtp status command in privileged EXEC mode.

Related Commands

Command Description

show vtp status

Displays general information about the VTP management domain, status, and counters.

vtp domain

Use the vtp domain VLAN database command to configure the VLAN Trunk Protocol (VTP) administrative domain.

vtp domain domain-name

Syntax Description

domain-name

ASCII string from 1 to 32 characters that identifies the VTP administrative domain for the switch. The domain name is case sensitive.

Defaults

No domain name is defined.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

The switch is in the no-management-domain state until you configure a domain name. While in the no-management-domain state, the switch does not transmit any VTP advertisements even if changes occur to the local VLAN configuration. The switch leaves the no-management-domain state after receiving the first VTP summary packet on any port that is currently trunking or after configuring a domain name using the vtp domain command. If the switch receives its domain from a summary packet, it resets its configuration revision number to zero. After the switch leaves the no-management-domain state, it can never be configured to reenter it until you clear the nonvolatile RAM (NVRAM) and reload the software.

Domain names are case sensitive.

Once you configure a domain name, it cannot be removed. You can only reassign it to a different domain.

Examples

The following example shows how to set the administrative domain for the switch:

Switch(vlan)# vtp domain OurDomainName

You can verify the previous commands by entering the show vtp status command in privileged EXEC mode.

Related Commands

Command Description

show vtp status

Displays general information about the VTP management domain, status, and counters.

vtp password

Configures the VTP administrative domain password.

vtp file

Use the vtp file global configuration command to modify the VLAN Trunk Protocol (VTP) configuration storage filename. Use the no form of this command to return the filename to its default name.

vtp file ifsfilename

no vtp file

Syntax Description

ifsfilename

The IOS IFS filename where the VTP VLAN configuration is stored.

Defaults

The default filename is flash:vlan.dat.

Command Modes

Global configuration

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

This command cannot be used to load a new database; it only renames the file in which the existing database is stored.

Examples

The following example shows how to rename the filename for VTP configuration storage to vtpfilename:

Switch(config)# vtp file vtpfilename

Related Commands

Command Description

vtp

Configures the VTP mode

vtp password

Use the vtp password VLAN database command to configure the VLAN Trunk Protocol (VTP) administrative domain password. Use the no form of this command to remove the password.

vtp password password-value

no vtp password password-value

Syntax Description

password

Set the password for the generation of the 16-byte secret value used in MD5 digest calculation to be sent in VTP advertisements and to validate received VTP advertisements.

password-value

ASCII string from 8 to 64 characters. The password is case sensitive.

Defaults

No password is defined.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

Passwords are case sensitive. Passwords should match on all switches in the same domain.

When the no vtp password form of the command is used, the switch returns to the no-password state.

Examples

The following example shows how to configure the VTP domain password:

Switch(vlan)# vtp password ThisIsOurDomain'sPassword

Related Commands

Command Description

vtp domain

Configures the VTP administrative domain.

vtp pruning

Use the vtp pruning VLAN database command to enable pruning in the VLAN Trunk Protocol (VTP) administrative domain. Use the no form of this command to disable pruning.

vtp pruning

no vtp pruning

Syntax Description

This command has no arguments or keywords.

Defaults

Pruning is disabled.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

If you enable pruning on the VTP server, it is enabled for the entire management domain.

Only VLANs included in the pruning-eligible list can be pruned.

VLANs 2 through 1001 are pruning-eligible on 2900 XL and 3500 XL trunk ports.

Pruning is support with VTP version 1 and version 2.

Examples

The following example shows how to enable pruning in the proposed new VLAN database:

Switch(vlan)# vtp pruning

You can verify the previous commands by entering the show vtp status command in privileged EXEC mode.

Related Commands

Command Description

show interface interface-id pruning

Displays pruning information for the trunk port.

show vtp status

Displays general information about the VTP management domain, status, and counters.

switchport trunk pruning

Configures the VLAN pruning-eligible list for ports in trunking mode.

vtp v2-mode

Use the vtp v2-mode VLAN database command to enable VLAN Trunk Protocol (VTP) version 2 in the administrative domains. Use the no form of this command to disable V2 mode.

vtp v2-mode

no vtp v2-mode

Syntax Description

This command has no arguments or keywords.

Defaults

VTP version 2 is disabled.

Command Modes

VLAN database

Command History

Release Modification

11.2(8)SA4

This command was first introduced.

Usage Guidelines

Toggling the V2 mode state modifies certain parameters of certain default VLANs.

Each VTP switch automatically detects the capabilities of all the other VTP devices. To use V2 mode, all VTP switches in the network must support version 2; otherwise, you must configure them to operate in VTP version 1 mode (no vtp v2-mode).

If you are using VTP in a Token Ring environment, VTP V2 mode must be enabled.

If you are configuring a Token Ring bridge relay function (TRBRF) or Token Ring concentrator relay function (TRCRF) VLAN media type, you must use version 2.

If you are configuring a Token Ring or Token Ring-NET VLAN media type, you must use version 1.

Examples

The following example shows how to enable V2 mode in the proposed new VLAN database:

Switch(vlan)# vtp v2-mode

You can verify the previous commands by entering the show vtp status command in privileged EXEC mode.

Related Commands

Command Description

show vtp status

Displays general information about the VTP management domain, status, and counters.

vtp

Configures the VTP mode.

vtp pruning

Enables pruning in the VTP administrative domain.

name	Name of the cluster up to 31 characters. Valid characters include only alphanumerics, dashes, and underscores.
command-switch-member-number	(Optional) Assign a member number to the command switch of the cluster. The range is from 0 to 15.
no	Remove all member switches and make the command switch a candidate.
default	Switch is not a command switch.

holdtime-in-secs	Duration in seconds before a switch (either a command or member switch) declares the other switch down. The range is from 1 to 300 seconds
no	Set the holdtime to the default value (80 seconds).
default	Set the holdtime to the default value (80 seconds)

n	VLAN ID of the new management VLAN. Valid VLAN IDs are from 1 to 1001.
no	Set the management VLAN to VLAN 1
default	Set the management VLAN to VLAN 1

n	(Optional) The number that identifies a cluster member. The range is from 0 to 15
mac-address H.H.H	MAC address of the member switch in hexadecimal format.
password enable-password	Enable password of the candidate switch. The password is not required if there is no password on the candidate switch.
no	Remove the specified member from the cluster.
default	Remove the specified member from the cluster.

no	Disable clustering on a switch.
default	Enable clustering on a switch.

Command	Description
cluster enable	Enables a switch as the cluster command switch, assigns a cluster name, and optionally assigns a member number to it.
show cluster	Displays the cluster status and a summary of the cluster to which the switch belongs.
show cluster candidates	Displays a list of candidate switches.
show cluster members	Displays information about the cluster members.

HSRP-group-name	Name of the HSRP group that is bound to the cluster. The group name is limited to 32 characters.
no	Unbind the cluster from the HSRP standby group.
default	Unbind the cluster from the HSRP standby group.

Command	Description
standby ip	Enables HSRP on the interface.
show cluster	Displays the cluster status and a summary of the cluster to which the switch belongs.
show standby	Displays standby group information.

interval-in-secs	Interval in seconds between heartbeat messages. The range is from 1 to 300 seconds.
no	Set the interval to the default value (8 seconds).
default	Set the interval to the default value (8 seconds).

device:	Device containing the file to be deleted. Valid devices include the switch Flash memory and ATM module files. To access the ATM module, specify the slot number (1 or 2).
filename	Name of file.

full	Port is in full-duplex mode.
half	Port is in half-duplex mode.
auto	Port automatically detects whether it should run in full- or half-duplex mode.

Command	Description
show running-config	Displays the running configuration on the switch.
speed	Specifies the speed of a Fast Ethernet port.

password	Provide access to enable mode with entry of the privileged command level password. A password must contain from 1 to 25 uppercase and lowercase alphanumeric characters.
succeed	Provide access to enable mode without further question.

Command	Description
enable	Accesses privileged EXEC mode.
show running-config	Displays the running configuration on the switch.

Command	Description
show running-config	Displays the running configuration on the switch.
tacacs-server authenticate enable	Indicates whether users can perform an attempted action under TACACS and extended TACACS.

Command	Description
abort	Abandons the proposed new VLAN database, exits VLAN database mode, and returns to privileged EXEC mode.
apply	Implements the proposed new VLAN database, increments the database configuration revision number, propagates it throughout the administrative domain, and remains in VLAN database mode.
reset	Abandons the proposed VLAN database and remains in VLAN database mode. Resets the proposed database to the currently implemented VLAN database on the switch.
show vlan	Displays the parameters for all configured VLANs in the administrative domain.
shutdown vlan	Shuts down (suspends) local traffic on the specified VLAN.
vlan database	Enters VLAN database mode from the command-line interface (CLI).

asymmetric	Enable the local port to perform flow control of the remote port. If the local port is congested, it can request the remote port to stop transmitting. When the congestion clears, the local port requests that the remote port begin transmitting.
symmetric	Enable the local port to perform flow control only if the remote port can also perform flow control of the local port. If the remote port cannot perform flow control, the local port also does not.

type	Type of interface to be configured. Can be Fast Ethernet, Gigabit Ethernet, or Asynchronous Transfer Mode (ATM).
slot	Slot number (0, 1, or 2). For an ATM module, use slot number 1 or 2.
port	Port ID.
vlan number	VLAN number from 1 to 1001 to be used as the management VLAN. Do not enter leading zeroes.

Command	Description
management	Shuts down the current management VLAN interface and enables the new management VLAN interface.
show interface	Displays the administrative and operational status of a switching (nonrouting) port.
shutdown	Disables a port and shuts down the management VLAN.

ip-address	IP address.
subnet-mask	Mask for the associated IP subnet.

Table of Contents

Cisco IOS Commands

VLAN Configuration Rules

local	(Optional) Select local password checking. Authentication is based on the username specified with the username global configuration command.
tacacs	(Optional) Select the Terminal Access Controller Access Control System (TACACS)-style user ID and password-checking mechanism.

Command	Description
enable password	Sets a local password to control access to various privilege levels.
password	Specifies a password on a line.
show running-config	Displays the running configuration on the switch.
username	Establishes a username-based authentication system.

default	Use the default list created with the AAA authentication login command.
list-name	Use the indicated list created with the AAA authentication login command.

Command	Description
clear mac-address-table	Deletes entries from the MAC address table.
mac-address-table dynamic	Adds dynamic addresses to the MAC address table.
mac-address-table secure	Adds secure addresses to the MAC address table.
port block	Blocks the flooding of unknown unicast or multicast packets to a port.
show cgmp	Displays the current state of the CGMP-learned multicast groups and routers.
show mac-address-table	Displays the MAC address table.

hw-addr	MAC address that is added to the table.
interface	Port to which packets destined for hw-addr are forwarded.
atm slot/port	(Optional) Add secure address to the ATM module in slot 1 or 2. The port is always 0 for an ATM interface.
vlan vlan-id	(Optional) The interface and vlan parameters together specify a destination to which packets destined for hw-addr are forwarded. The vlan keyword is optional if the port is a static-access VLAN port. In this case, the VLAN assigned to the port is assumed to be that of the port associated with the MAC address. This keyword is required for multi-VLAN and trunk ports. The vlan-id is the ID of the VLAN to which secure entries are added. Valid IDs are 1 to 1005; do not enter leading zeroes.

hw-addr	MAC address to add to the address table.
in-port	Input port from which packets received with a destination address of hw-addr are forwarded to the list of ports in the out-port-list. The in-port must belong to the same VLAN as all the ports in the out-port-list
out-port-list	List of ports to which packets received on ports in in-port are forwarded. All ports in the list must belong to the same VLAN.
atm slot/port	(Optional) Add static addresses to ATM module in slot 1 or 2. The port is always 0 for an ATM interface.
vlan vlan-id	(Optional) The interface and vlan parameters together specify a destination to which packets destined for the specified MAC address are forwarded. The vlan keyword is optional if all the ports specified by in-port and out-port-list are static-access VLAN ports. The VLAN assigned to the ports is assumed. This keyword is required for multi-VLAN and trunk ports. Dynamic-access ports cannot be included in static addresses as either the source (inport) or destination (outport). The vlan keyword is required on trunk ports to specify to which VLAN the static address is assigned. The vlan-id is the ID of the VLAN to which static address entries are forwarded. Valid IDs are 1 to 1005; do not enter leading zeroes.

Command	Description
cluster management-vlan	Changes the management VLAN for the entire cluster.
interface vlan	Configures an interface type, creates a switch virtual interface to be used as the management VLAN interface, and enters interface configuration mode
show interface vlan number	Displays the administrative and operational status of a switching (nonrouting) port.

query-only	Enable only NTP control queries. See RFC 1305 (NTP version 3).
serve-only	Enable only time requests.
serve	Enable time requests and NTP control queries, but does not enable the system to synchronize to the remote system.
peer	Enable time requests and NTP control queries; enable the system to synchronize to the remote system.
access-list-number	Number (1 to 99) of a standard IP access list

Command	Description
access-list	Differentiates one packet from another so that different treatment can be applied.
show running-config	Displays the running configuration on the switch.

Command	Description
ntp authentication-key	Defines an authentication key for NTP.
ntp trusted-key	Authenticates the identity of a system to which NTP will synchronize.
show running-config	Displays the running configuration on the switch.