cc/td/doc/product/lan/28201900/1928v8x
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Table of Contents

Command Descriptions

Command Descriptions

This chapter is a command-by-command description of the Cisco CLI commands for the Catalyst  2820  series and Catalyst  1900  series switches.

address-violation

Use the address-violation global configuration command to specify the action for a port address violation. Use the no address-violation command to set the switch to its default value (suspend). An address violation occurs when a secured port receives a source address that has been assigned to another secured port or when a port tries to learn an address that exceeds its address table size limit.

address-violation {suspend | disable | ignore}
no address-violation

Syntax Description

suspend

Suspend port on address violation. A suspended port is temporarily disabled until a certain number of frames with the proper address is received.

disable

Disable port on address violation.

ignore

Ignore address violation.

Default

The port is suspended on address violation.

Command Mode

Global configuration

Example

This command causes the switch to disable the port on address violation.

hostname(config)# address-violation 
disable
Related Commands

port (secure)
show (port system)

autobaud

Use the autobaud line-configuration command to enable remote baud-rate matching. Use the no  autobaud command to disable remote baud-rate matching.

autobaud
no autobaud

Syntax Description

This command has no arguments or keywords.

Default

Remote baud-rate matching is enabled.

Command Mode

Line configuration

Example

This example shows how to enable remote baud-rate matching.

hostname(config-line)# autobaud
Related Commands

databits
line (console)
modem (dialin)
parity
speed
stopbits
terminal

back-pressure

Use the back-pressure global configuration command to enable back pressure. Use the no  back-pressure command to disable back pressure.

back-pressure
no back-pressure

Syntax Description

This command has no arguments or keywords.

Default

Back pressure is disabled.

Command Mode

Global configuration

Usage Guidelines

When the back-pressure command is enabled, the switch forces a collision when there is no buffer to receive frames. This collision causes the transmitter to retransmit dropped frames immediately, increasing performance. The command is valid only for a 10BaseT port operating in half-duplex mode.

Example

This example shows how to enable back pressure.

hostname(config)# back-pressure
Related Commands

configure
duplex
show (interfaces)
show (port system)

bridge

Use the bridge global configuration command to configure the parameters of a bridge group. Use the no  bridge command to reset the bridge group parameters to its default values.

bridge bridge-group
no bridge bridge-group

Syntax Description

bridge-group

Number from 1 to 4.

Default

The default is 15 seconds.

Command Mode

Global configuration

Usage Guidelines

This command is available only when bridge groups are enabled.

Example

The following example shows how to select a bridge group for configuration.

hostname(config)# bridge 
Related Commands

bridge (hello-time)
bridge (max-age)
bridge (priority)
bridge-group (allow-overlap)
bridge-group (enable)
show (bridge-group)
show (spantree bridge-group)
spantree (bridge-group)

bridge (forwarding-time)

Use the bridge forwarding-time global configuration command to set the Spanning-Tree Protocol (STP) forward-delay time for a particular bridge group. Use the no  bridge forwarding-time command to reset the forward-delay time to its default value.

bridge bridge-group forwarding-time time
no bridge bridge-group forwarding-time

Syntax Description

bridge-group

Number from 1 to 4.

time

Number from 4 to 30 (seconds).

Default

The default is 15 seconds.

Command Mode

Global configuration

Usage Guidelines

This command is available only when bridge groups are enabled.

Example

The following example shows how to set the forward-delay time to 10 seconds for bridge-group 1.

hostname(config)# bridge 1 forwarding-time 10
Related Commands

bridge (hello-time)
bridge (max-age)
bridge (priority)
bridge-group (allow-overlap)
bridge-group (enable)
show (bridge-group)
show (spantree bridge-group)
spantree (bridge-group)

bridge-group

Use the bridge-group interface configuration command to modify the assignments of ports to bridge groups. Use the no  bridge-group command to remove ports from a bridge group.

bridge-group bridge-group
no bridge-group bridge-group

Syntax Description

bridge-group

Number from 1 to 4.

Default

All ports are assigned to bridge group 1.

Command Mode

Interface configuration

Usage Guidelines

This command is available only when bridge groups are enabled.

If bridge groups can overlap, the bridge-group command adds a port to the bridge group specified by the bridge-group argument. If bridge groups cannot overlap, the port is moved from its current bridge group to the specified bridge group.

Example

The following example shows how to assign the port ethernet 0/1 to bridge group 2:

hostname(config)# interface eth 0/1
hostname(config-if)# bridge-group 2
Related Commands

bridge (forwarding-time)
bridge (hello-time)
bridge (max-age)
bridge (priority)
bridge-group (allow-overlap)
bridge-group (enable)
show (bridge-group)
show (spantree bridge-group)

bridge-group (allow-overlap)

Use the bridge-group allow-overlap global configuration command to allow ports to belong to multiple bridge groups. Use the no  bridge-group allow-overlap command to prevent ports from belonging to multiple bridge groups.

bridge-group allow-overlap
no
bridge-group allow-overlap

Syntax Description

This command has no additional arguments or keywords.

Default

Ports are prevented from belonging to multiple bridge groups.

Command Mode

Global configuration

Usage Guidelines

This command is available only when bridge groups are enabled.

You cannot disable overlapping bridge groups when ports belong to multiple bridge groups.

Example

The following example shows how to permit ports to become members of multiple bridge groups.

hostname(config)# bridge-group allow-overlap
Related Commands

bridge (forwarding-time)
bridge (hello-time)
bridge (max-age)
bridge (priority)
bridge-group
bridge-group (enable)
show (bridge-group)
show (spantree bridge-group)
spantree (bridge-group)

bridge-group (enable)

Use the bridge-group enable global configuration command to enable port grouping using bridge groups. Use the no  bridge-group enable command to use virtual LANs (VLANs) as the port grouping method.

bridge-group enable
no
bridge-group enable

Syntax Description

This command has no additional arguments or keywords.

Default

Bridge groups are disabled.

Command Mode

Global configuration

Usage Guidelines

When you use the bridge-group enable command or the no bridge-group enable command, the switch resets.

When bridge groups are disabled, the command bridge-group enable is the only available bridge-group command. Also, the following switch-feature commands are not available when bridge groups are enabled:

clear (vtp statistics)

show (vlan-membership)

trunk-vlan

ip (mgmt-vlan)

show (vlan-membership server)

uplink-fast

pagp-port-priority

show (vtp)

uplink-fast (multicast-rate)

port-channel (mode)

show (vtp statistics)

vlan

port-channel (preserve-order)

spantree-option (vlan)

vlan-membership

port-channel template-port

spantree-template (forwarding-time)

vlan-membership (reconfirm)

show (spantree-option)

spantree-template (hello-time)

vlan-membership (server)

show (spantree-template)

spantree-template (max-age)

vlan-membership (server retry)

show (trunk)

spantree-template (priority)

vtp

show (uplink-fast)

spantree-template (vlan)

vtp trunk pruning-disable

show (vlan)

trunk

Example

The following example shows how to enable bridge groups:

hostname(config)# bridge-group enable
Related Commands

bridge (forwarding-time)
bridge (hello-time)
bridge (max-age)
bridge (priority)
bridge-group
bridge-group (allow-overlap)
show (bridge-group)
show (spantree bridge-group)
spantree (bridge-group)

bridge (hello-time)

Use the bridge hello-time global configuration command to configure the hello time in Spanning-Tree Protocol (STP) for a bridge group. Use the no  bridge hello-time command to use the default value.

bridge bridge-group hello-time time
no bridge bridge-group hello-time

Syntax Description

bridge-group

Number from 1 to 4.

time

Number from 1 to 10 (seconds).

Default

The time argument default is 2 seconds.

Command Mode

Global configuration

Usage Guidelines

This command is available only when bridge groups are enabled.

Example

The following example shows how to configure the hello time for STP to 3  seconds for bridge group  2.

hostname(config)# bridge 2 hello-time 3
Related Commands

bridge (forwarding-time)
bridge (max-age)
bridge (priority)
bridge-group
bridge-group (allow-overlap)
bridge-group (enable)
show (bridge-group)
show (spantree bridge-group)
spantree (bridge-group)

bridge (max-age)

Use the bridge max-age global configuration command to configure the maximum age time in Spanning-Tree Protocol (STP) for a bridge group. Use the no  bridge max-age command to set the argument to its default value.

bridge bridge-group max-age time
no bridge bridge-group max-age

Syntax Description

bridge-group

Number from 1 to 4.

time

Number from 6 to 40 (seconds).

Default

The time argument default is 20 seconds.

Command Mode

Global configuration

Usage Guidelines

This command is available only when bridge groups are enabled.

Example

The following example shows how to set the max-age time for STP to 22  seconds for bridge group 1.

hostname(config)# bridge 1 max-age 22
Related Commands

bridge (forwarding-time)
bridge (hello-time)
bridge (priority)
bridge-group
bridge-group (allow-overlap)
bridge-group (enable)
show (bridge-group)
show (spantree bridge-group)
spantree (bridge-group)

bridge (priority)

Use the bridge priority global configuration command to configure the Spanning-Tree Protocol (STP) bridge priority for a bridge group. Use the no  bridge priority command to reset the bridge priority to its default value.

bridge bridge-group priority priority
no bridge bridge-group priority priority

Syntax Description

Tips

Number from 1 to 4.

priority

Number from 1 to 65,535.

Default

The priority default is 32,768.

Command Mode

Global configuration

Usage Guidelines

This command is available only when bridge groups are enabled.

Example

The following example shows how to configure STP bridge priority to 33,000 for bridge group  1.

hostname(config)# bridge 1 priority 33000
Related Commands

bridge (forwarding-time)
bridge (hello-time)
bridge (max-age)
bridge-group
bridge-group (allow-overlap)
bridge-group (enable)
bridge-group
show (spantree bridge-group)
spantree (bridge-group)

cdp (enable)

Use the cdp enable interface configuration command to enable Cisco Discovery Protocol (CDP) on a switched port interface. Use the no  cdp enable command to disable CDP on an interface.

cdp enable
no cdp enable

Syntax Description

This command has no additional arguments or keywords.

Default

CDP is enabled on all interfaces.

Command Mode

Interface configuration

Usage Guidelines

The cdp enable command is not available on repeater ports.

Example

The following example shows how to disable CDP on interface fa 0/27.

hostname(config)# interface fastethernet 0/27
hostname(config-if)# no cdp enable
Related Commands

cdp (holdtime)
cdp (timer)
show (cdp interface)
show (cdp neighbors)

cdp (holdtime)

Use the cdp holdtime global configuration command to set the Cisco Discovery Protocol (CDP) hold time. Use the no  cdp holdtime command to use its default value.

cdp holdtime holdtime
no cdp holdtime

Syntax Description

holdtime

Number of seconds receiver keeps packet (5  to  255).

Default

180 seconds

Command Mode

Global configuration

Example

This example shows how to set the CDP holdtime to 15 seconds.

hostname(config)# cdp holdtime 15
Related Commands

cdp (enable)
cdp (timer)
show (cdp interface)
show (cdp neighbors)

cdp (timer)

Use the cdp timer global configuration command to specify the rate at which Cisco Discovery Protocol (CDP) packets are sent. Use the no  cdp timer command to reset the CDP rate to its default value.

cdp timer timer
no cdp timer

Syntax Description

timer

Number between 5 and 900 (seconds).

Default

60 seconds

Command Mode

Global configuration

Example

This example shows how to set the CDP packet rate to once in 5 seconds.

hostname(config)# cdp timer 5
Related Commands

cdp (enable)
cdp (holdtime)
show (cdp interface)
show (cdp neighbors)

cgmp

Use the cgmp global configuration command to enable Cisco Group Management Protocol (CGMP) functionality. Use the no  cgmp command to disable CGMP.

cgmp
no cgmp

Syntax Description

This command has no arguments or keywords.

Default

CGMP is disabled.

Command Mode

Global configuration

Example

This example shows how to disable CGMP.

hostname(config)# no cgmp
Related Commands

cgmp (hold-time)
cgmp (remove)
show (cgmp)

cgmp (hold-time)

Use the cgmp hold-time global configuration command to set the Cisco Group Management Protocol (CGMP) hold time. Use the no  cgmp hold-time command to the default hold time.

cgmp hold-time hold_time
no cgmp hold-time

Syntax Description

holdtime

Number between 5 and 900 (seconds).

Defaults

Default hold time is 300 seconds.
CGMP hold time is disabled.

Command Mode

Global configuration

Example

This example shows how to set the CGMP hold time to 40 seconds.

hostname(config)# cgmp hold-time 40

This example shows how to disable CGMP hold time.

hostname(config)# no cgmp hold-time
Related Commands

cgmp
cgmp (remove)
show (cgmp)

cgmp (remove)

Use the cgmp remove global configuration command to remove an address that has been added to an interface due to Cisco Group Management Protocol (CGMP) activity.

cgmp remove mac-address

Syntax Description

mac-address

MAC address.

Default

None

Command Mode

Global configuration

Example

This example shows how to remove the address 0100.5e00.0203 from the interface.

hostname(config)# cgmp remove 0100.5e00.0203
Related Commands

cgmp
cdp (holdtime)
show (cgmp)

clear (counters)

Use the clear counters privileged Exec command to clear interface counters for a switched port interface.

clear counters [type module/port]

Syntax Description

type

Interface type: ethernet, fastethernet, fddi, atm, or port-channel.

module

Module interface number:

0 for fixed
1 or A for module A
2 or B for module B

port

Port interface number ranging from 1 to 28:

1 to 25 Ethernet (fixed)
26, 27 Fast Ethernet (fixed)
28 Port channel

Command Mode

Privileged Exec

Usage Guidelines

If you don't specify type module/port, the switch will clear the counters for all interfaces.

Example

This example shows how to clear counters for the Ethernet port 1.

hostname# clear counters ethernet 0/1
Related Commands

interface
show (interfaces)

clear (mac-address-table)

Use the clear mac-address-table privileged Exec command to remove a specified address (or set of addresses) from the MAC address table.

clear mac-address-table [dynamic | restricted static | permanent] [address mac-address]
 [interface type module/port]

Syntax Description

dynamic

Clears only dynamic addresses.

restricted static

Clears only restricted static addresses.

permanent

Clears only permanent addresses.

address

Clears only a specified address.

mac-address

Target MAC address.

interface

Clears all addresses for an interface.

type

Interface type: ethernet, fastethernet, fddi, line and atm, or port-channel.

module

The module interface number.

0 for fixed
1 or A for module A
2 or B for module B

port

Port interface number ranging from 1 to 28:

1 to 25 Ethernet (fixed)
26, 27 Fast Ethernet (fixed)
28 Port-channel

Default

The dynamic addresses are cleared.

Command Mode

Privileged Exec

Usage Guidelines

If clear mac-address-table is invoked with no options, all dynamic addresses are removed. If you specify an address but do not specify an interface, the address is deleted from all interfaces. If you specify an interface but do not specify an address, all addresses on the specified interface are removed.

If a targeted address is not present in the MAC forwarding table, the following error message appears:

MAC address not found
Example

This example shows how to clear all dynamic addresses in the MAC forwarding table.

hostname# clear mac-address-table

This command clears the permanent address 0040.C80A.2F07 on the interface eth 0/1.

hostname# clear mac-address-table permanent address 0040.C80A.2F07 interface ether 0/1
Related Commands

mac-address-table (permanent)
mac-address-table (restricted static)
show (mac-address-table)
show (mac-address-table security)

clear (uplink-fast statistics)

Use the clear uplink-fast statistics privileged Exec command to clear all Uplink Fast counter statistics to zero.

clear uplink-fast statistics

Syntax Description

This command has no additional arguments or keywords.

Command Mode

Privileged Exec

Usage Guidelines

This command is not functional when bridge groups are enabled.

Example

This example shows how to clear all Uplink Fast counters to zero:

hostname# clear uplink-fast statistics
Related Commands

uplink-fast
show (uplink-fast)
show (uplink-fast statistics)

clear (vtp statistics)

Use the clear vtp statistics privileged Exec command to clear all VTP statistics counters.

clear vtp statistics

Syntax Description

This command has no additional arguments or keywords.

Command Mode

Privileged Exec

Usage Guidelines

This command is not functional when bridge groups are enabled.

Example

This example shows how to clear all counters of VTP statistics.

hostname# clear vtp statistics
Related Commands

show (vtp)
show (vtp statistics)
vtp
vtp trunk pruning-disable

configure

Use the configure privileged Exec command to enter the global configuration mode from the default terminal. Use the terminal keyword to specify a specific terminal.

config [terminal terminal]

Syntax Description

terminal

Name of target terminal.

Command Mode

Privileged Exec

Example

This example shows how to enter global configuration mode from your current terminal.

hostname# configure
hostname(config)#

This example shows how to enter global configuration mode from terminal t.

hostname# configure t
Related Commands

end
exit

copy (nvram tftp)

Use the copy nvram tftp privileged Exec command to upload the running nondefault configuration to a TFTP server host and destination file dst_file.

copy nvram tftp://host/dst_file

Syntax Description

host/dst_file

Target host and destination file where host is an IP address or a hostname.

Command Mode

Privileged Exec

Usage Guidelines

Error messages appear in the following situations:

If other download or upload operations (firmware, configuration, web pages) are in progress, the following error message appears:

Other downloads or uploads in progress. Please wait until existing download or upload 
is completed.
Example

This example shows how to upload the NVRAM configuration to the host spaniel with TFTP using destination file matilda.cfg.

hostname# copy nvram tftp://spaniel/matilda.cfg
Configuration upload is successfully completed

If the upload fails, the following message displays:

Error: Configuration upload operation failed
Related Commands

copy (tftp)
show (running-config)
show (version)

copy (tftp)

Use the copy tftp privileged Exec command to download a configuration or operation code file from the TFTP server.

copy tftp://host/src_file {opcode [type module] | nvram}

Syntax Description

//host/src_file

Host and source file where host is an IP address or hostname. Source filename can be up to 80 characters.

opcode

Download new operation code.

type

Interface type. The valid values are fddi and atm.

module

Interface number: 1 or A for module A, and 2 or B for module B.

nvram

Download a configuration file into NVRAM.

Command Mode

Privileged Exec

Usage Guidelines

You must specify type and module if the download is for a module.

Downloaded configuration files are executed immediately. Any error during execution appears on the console screen if the console is connected to the switch. The switch attempts to execute all commands irrespective of failures.

When downloading an operation code file, the entire system (including other CLI sessions) is inactive for about 30 seconds after the file is retrieved.

Error messages appear in the following situations:

If other download or upload operations (firmware, configuration, web pages) are in progress, the following message appears:

Other downloads or uploads in progress. Please wait until existing download or upload 
is completed.
Examples

This example shows how to download new system operational code op.bin from host spaniel.

hostname# copy tftp://spaniel/op.bin opcode

This example shows how to download new FDDI operational code fddi.bin from host spaniel to the FDDI module in slot A.

hostname# copy tftp://spaniel/fddi.bin opcode fddi A
TFTP successfully downloaded operational code

This example shows how to download a configuration file matilda.cfg from host spaniel.

hostname# copy tftp://spaniel/matilda.cfg nvram
TFTP successfully downloaded configuration file

If the download fails, the following message displays:

Error: TFTP failed to download the configuration file
Related Commands

copy (nvram tftp)
show (running-config)
show (version)

copy (xmodem)

Use the copy xmodem privileged Exec command to download an operation code or firmware file using the XMODEM protocol.

copy xmodem: src_file opcode [type module]

Syntax Description

src_file

Firmware filename.

opcode

Download new operation code.

type

Interface type. Valid values are fddi and atm.

module

Interface number: 1 or A for module 1, 2 or B for module 2.

Default

If you specify type and module, the file copies the code or file to the specified module. When type and module are not specified, the file copies them to the switch firmware.

Command Mode

Privileged Exec

Usage Guidelines

You cannot enter any new information or commands until the download is completed. After downloading operation code file, the entire system (including other CLI sessions) is inactive for about 30 seconds.

Example

This example shows how to download the operational code file.

hostname# copy xmodem:op_code.bin opcode

This shows how to download new FDDI operational code fddi.bin to module slot A.

hostname# copy xmodem:fddi.bin opcode fddi A
Related Commands

copy (tftp)
copy (xmodem)
show (running-config)
show (version)

databits

Use the databits line-configuration command to set the data bits per character for a port. Use the no  databits command to set the number of data bits to its default value.

databits [7 | 8]
no databits

Syntax Description

7 or 8

Number of data bits per character.

Default

8 data bits per character.

Command Mode

Line configuration

Example

This example shows how to set the number of data bits per character to 7.

hostname(config-line)# databits 7
Related Commands

autobaud
line (console)
modem (dialin)
parity
show (line)
speed
stopbits
terminal

delete (nvram)

Use the delete nvram privileged Exec command to reset the system or module configuration to factory defaults.

delete nvram [type module]

Syntax Description

type

Interface type. Valid values are fddi and atm.

module

Module interface number: 1 or A for module A, and 2 or B for module B.

Default

The system or module is reset to factory defaults.

Command Mode

Privileged Exec

Usage Guidelines

Note If you reset the switch using the delete nvram command, you reset both the system and the module. However, resetting the switch to factory defaults does not reset module arguments stored in the module NVRAM.
Examples

This example shows how to reset system configuration to factory defaults.

hostname(config)# delete nvram
This command resets the switch with factory defaults. All parameters will revert to 
their default factory settings. All static system and dynamic addresses will be 
removed.
Reset system with factory defaults, [y]es or [n]o?

Press Y or N to proceed.

This example shows how to reset the ATM module in slot A to factory defaults.

hostname(config)# delete nvram atm 1
This command resets the module and restores all settings to factory defaults.  
The module is deinstalled until it successfully completes its self tests.
Reset module with factory defaults, [Y]es or [N]o?

Press Y or N to proceed.

Related Commands

copy (tftp)
reload

delete (vtp)

Use the delete vtp privileged Exec command to set the system VLAN trunk protocol (VTP) configuration back to factory defaults.

delete vtp

Syntax Description

This command has no additional arguments or keywords.

Command Mode

Privileged Exec

Usage Guidelines

Resetting the system VTP configuration also resets the system. This command first prompts the user to confirm:

This command resets the switch VTP arguments to factory defaults. All other arguments 
will be unchanged.
Reset system VTP arguments to factory defaults, [y]es or [n]o?

Press Y or N to proceed.

Example

This example shows how to reset system VTP configuration to factory defaults.

hostname# delete vtp
Related Commands

clear (vtp statistics)
show (vtp)
show (vtp statistics)
vtp
vtp trunk pruning-disable

description

Use the description interface configuration command to describe or name an interface. Use the no  description command to remove a description from an interface.

description name-string
no description

Syntax Description

name-string

A text description between 1 and 80 alphanumeric characters.

Default

This command has no default value.

Command Mode

Interface configuration

Usage Guidelines

To use the description command, you must first identify the interface you want while working from global configuration mode. Enter the interface command with an interface identifier to enter interface configuration mode, where you can then enter a description.

If you want to enter a description with spaces between characters, you must enclose the string in quotation marks (see "Paul's machine" example, below)

Example

This example shows how to give the name Hal to Ethernet port 1.

hostname(config)# interface ether 0/1
hostname(config-if)# description Hal

This example shows how to give the name Paul's machine to ATM module 1.

hostname(config)# interface atm A
hostname(config-if)# description "Paul's machine"

This example shows how to give the description server1 to port 1 on ATM module 1.

hostname(config)# interface atm A
hostname(config-if)# description server1
Related Commands

interface
show (cdp interface)
show (interfaces)

disable

Use the disable privileged Exec command to exit the privileged access level and enter user levels.

disable

Syntax Description

This command has no arguments or keywords.

Command Mode

Privileged Exec

Example

This example shows how to exit the privileged Exec mode and change to user Exec mode.

hostname# disable
Related Command

enable
configure

duplex

Use the duplex interface configuration command to enable duplex mode for an interface.

duplex {auto | full | full-flow-control | half}

Syntax Description

auto

Auto-negotiation of duplex mode.

full

Full-duplex mode.

full-flow-control

Force full-duplex mode with flow control.

half

Half-duplex mode.

Defaults

For 100-Mbps TX ports: duplex auto.
For all other ports that support half- and full-duplex: duplex half.

Command Mode

Interface configuration

Usage Guidelines

Use the auto argument only for fixed Fast Ethernet TX ports. In auto-negotiation mode, the switch attempts to negotiate full-duplex connectivity with the connecting device. If negotiation is successful, the port operates in full-duplex mode. If the connecting device is unable to operate in full-duplex, the port operates in half-duplex. This process is repeated whenever there is a change in link status.

Example

This example shows how to set the port to full-duplex mode.

hostname(config-if)# duplex full
Related Commands

interface
show (interfaces)
back-pressure

ecc

Use the ecc global configuration command to allow frames to be discarded early when a port becomes congested, which limits the number of frames queued on a port. Use the no  ecc command to disable congestion control.

ecc {10M | A | B} {adaptive | moderate-aggressive | aggressive}
no ecc [10M | A | B]

Syntax Description

10M

Congestion control for 10-Mbps ports.

A

Congestion control for port A. For single Fast Ethernet fixed and modular ports only.

B

Congestion control for port B. For single Fast Ethernet fixed and modular ports only.

adaptive

Adaptive congestion control.

moderate-aggressive

Moderately aggressive congestion control.

aggressive

Aggressive congestion control.

Default

Enhanced congestion control is disabled.

Command Mode

Global configuration

Examples

This example shows how to set enhanced congestion control for the 10-Mbps Ethernet ports to adaptive.

hostname(config)# ecc 10m adaptive

This example shows how to set enhanced congestion control for Fast Ethernet port A to aggressive.

hostname(config)# ecc A aggressive
Related Command

show (port system)

enable

Use the enable privileged Exec command to enter privileged Exec mode.

enable [access-level]

Syntax Description

access-level

Either 1 (user Exec level) or 15 (privileged Exec level).

Default

The access-level default for initial login is 1. The default access level after login is 15.

Command Mode

Privileged Exec

Usage Guidelines

If a password is configured, you are prompted for the password:

Password:

You are allowed three attempts to provide the correct password. The same prompt is repeated until you enter the correct password or you exceed the maximum number of attempts. If the password fails after the maximum attempts, the following error message appears:

Bad password.
Example

This example shows you how to move from user Exec mode access to the privileged Exec mode access.

hostname> enable
hostname#
Related Command

disable

enable (password)

Use the enable password global configuration command to set the password for an access level. Use the no  enable  password command to clear the password.

enable password level level password
no enable password level level

Syntax Description

level

Level for which the password applies:

1  User Exec privileges.
15  Privileged Exec privileges.

password

A string of between 4 and 12 alphanumeric characters (not case sensitive).

Default

No passwords are set. Privilege level defaults to level 15.

Command Mode

Global configuration

Usage Guidelines

Use the level 1 or level 15 password to log into the CLI. The level 15 password can also be used to log into menu and enable commands.

If you enter a password that is shorter than 4 characters or longer than 8 characters, the following message appears:

Password must be between 4 and 8 characters long.
Examples

Both of these examples show how to set the privileged Exec password to willow.

hostname(config)# enable password willow
hostname(config)# enable password level 15 willow

This example shows how to set the user Exec password to minnow.

hostname(config)# enable password level 1 minnow

enable (use-tacacs)

Use the enable use-tacacs global configuration command to use the Cisco Terminal Access Controller Access Control System (TACACS+) for authentication of enable passwords used to change the user privilege. Use the no enable use-tacacs command to turn off authentication for enable passwords.

enable use-tacacs
no enable use-tacacs

Syntax Description

This command has no additional arguments or keywords.

Default

Disabled.

Command Mode

Global configuration

Usage Guidelines

If you do not use TACACS+ to authenticate enable passwords, local authentication has control.

Example

This example shows how to use TACACS+ for authentication of enable passwords.

hostname(config)# enable use-tacacs
Related Commands

login (tacacs)
show (tacacs)
tacacs-server (attempts)
tacacs-server (directed-request)
tacacs-server (host)
tacacs-server (key)
tacacs-server (last-resort)
tacacs-server (timeout)

end

Use the end command from interface-configuration mode (config-if) and line-configuration mode (config-line) to exit the current mode and enter global configuration mode. Use the end command from global configuration mode to exit it and enter privileged Exec mode. Use the end command from privileged Exec mode to exit the system and terminate the console/telnet session.

end

Syntax Description

This command has no arguments or keywords.

Default

None

Command Mode

All configuration modes.

Example

This example shows how to exit the global configuration mode and enter privileged Exec mode.

hostname(config)# end
hostname#
Related Commands

exit
configure
interface
line (console)

exit

Use the exit configuration command to exit the system or current configuration mode.

exit

Syntax Description

This command has no arguments or keywords.

Command Mode

All configuration modes.

Usage Guidelines

If the current mode is privileged or user Exec, this command exits the system and terminates the console/telnet session. If the current mode is global configuration, this commands sets the mode to privileged Exec. If the current mode is other than global configuration, this command sets the mode to global configuration.

Example

This example shows how to exit from global configuration mode and enter privileged Exec mode:

hostname(config)# exit
hostname#

This example shows how to exit from interface configuration mode and enter global configuration mode:

hostname(config-if)# exit
hostname(config)#
Related Commands

configure
end
interface
line (console)

fddi (authorization)

Use the fddi authorization FDDI interface configuration command to enable authorization checking for the station management (SMT) entity. Use the no  fddi authorization command to disable authorization checking.

fddi authorization
no fddi authorization

Syntax Description

This command has no additional arguments or keywords.

Default

FDDI authorization is disabled.

Command Mode

FDDI interface configuration

Usage Guidelines

When authorization string checking is enabled, the FDDI module uses the current authorization string to verify SMT requests from remote stations. This command is only valid within FDDI module interface-configuration mode.

Example

This example shows how to enable authorization string checking.

hostname(config-if)# fddi authorization

This example shows how to disable authorization string checking.

hostname(config-if)# no fddi authorization
Related Commands

interface

show (interfaces)

fddi (auth-string)

Use the fddi auth-string interface configuration command to assign a new authorization string value used in the verification of station management (SMT) requests. Use the no  fddi auth-string command to clear the existing authorization string.

fddi auth-string string
no fddi auth-string

Syntax Description

string

A string of 4 to 80 alphanumeric characters entered in multiples of 4 characters.

Default

No FDDI authorization string is set.

Command Mode

Interface configuration

Usage Guidelines

This command is only valid within FDDI module interface-configuration mode.


Note You must enter an authorization string with a number of characters (including punctuation and numbers) that is divisible by 4.
Example

This example shows how to assign the authorization string value check_it (8 characters).

hostname(config-if)# fddi auth-string check_it
Related Commands

interface
show (interfaces)

fddi (notify-timer)

Use the fddi notify-timer interface configuration command to assign a new timer value for the Neighbor Notification Protocol. Use the no fddi notify-timer command to set the timer value to module defaults.

fddi notify-timer seconds
no fddi notify-timer

Syntax Description

seconds

A number between 2 and 30 seconds.

Default

30 seconds.

Command Mode

Interface configuration.

Usage Guidelines

This command is only valid within FDDI module interface-configuration mode.

Example

This example shows how to set the notify timer to 15 seconds.

hostname(config-if)# fddi notify-timer 15
Related Commands

interface
show (interfaces)

fddi (novell-snap-translation)

Use the fddi novell-snap-translation interface configuration command to define how to translate Novell Subnetwork Access Protocol (SNAP) FDDI frames from FDDI ring to Ethernet. Use the no no fddi novell-snap-translation command to set the translate value to module defaults.

fddi novell-snap-translation {automatic | ethernet-8023 | ethernet-snap | ethernet-II | drop}
no fddi novell-snap-translation

Syntax Description

automatic

Automatic packet recognition and translation for IPX networks of FDDI modules.

drop

Translate frames using Drop protocol.

ethernet-8023

Translate frames using Ethernet 802.3 protocol.

ethernet-II

Translate frames using Ethernet II protocol.

ethernet-snap

Translate frames using Ethernet SNAP.

Default

Automatic packet recognition is enabled.

Command Mode

Interface configuration

Usage Guidelines

This command is only valid within FDDI module interface-configuration mode.

Example

This example shows how to enable automatic packet recognition and translation for IPX networks of FDDI modules.

hostname(config-if)# fddi novell-snap-translation automatic
Related Commands

interface
show (interfaces)
fddi (unmatched-snap-translation)

fddi (unmatched-snap-translation)

Use the fddi unmatched-snap-translation interface configuration command to select which FDDI-to-Ethernet translation protocol to use for packets whose destinations cannot be determined from the Novell Subnetwork Access Protocol (SNAP) translation table.

fddi unmatched-snap-translation {all | ethernet-8023 | ethernet-snap | ethernet-II | drop}
no fddi unmatched-snap-translation

Syntax Description

all

Ethernet 802.3, Ethernet SNAP, and Ethernet II are all used.

drop

Translate frames using Drop protocol.

ethernet-8023

Translate frames using Ethernet 802.3 protocol.

ethernet-II

Translate frames using Ethernet SNAP.

ethernet-snap

Translate frames using Ethernet II protocol.

Default

All translation protocols are enabled.

Command Mode

Interface configuration

Usage Guidelines

This command is valid only when you select automatic as the SNAP translation format and you enter the command within FDDI module interface-configuration mode.

Example

This example shows how to select FDDI-to-Ethernet 802.3 translation for FDDI packets with unmatched destination addresses.

hostname(config-if)# fddi unmatched-snap-translation ether802.3
Related Commands

interface
show (interfaces)
fddi (novell-snap-translation)

hostname

Use the hostname global configuration command to set the system name. Use the no  hostname command to clear the name.

hostname name
no hostname

Syntax Description

name

System name between 1 and 255 alphanumeric characters.

Default

There is no default for this command.

Command Mode

Global configuration

Example

This example shows how to set the system name to the string Zorro.

2820(config)# hostname Zorro
Zorro(config)#
Related Command

show (snmp hostname)

interface

Use the interface global configuration command to choose an interface type and to enter interface configuration mode.

interface type module/port

Syntax Description

type

Interface type: ethernet, fastethernet, fddi, atm, and port-channel.

module

Module interface number:

0 for fixed
1 or A for module A
2 or B for module B

port

Port interface number ranging from 1 to 27:

1 to 25 Ethernet (fixed)
26, 27 Fast Ethernet (fixed)
1 to 4 Fast Ethernet (4-port Fast Ethernet repeater module)
1 to 8 Fast Ethernet (8-port Fast Ethernet repeater module)

Default

No default interface.

Command Mode

Global configuration

Example

This example shows how to enable configuration on Ethernet port 1.

hostname(config)# interface ethernet 0/1

This example shows how to enable configuration on ATM module 1.

hostname(config)# interface atm 1
Related Commands

end
exit
show (interfaces)

ip (address)

Use the ip address global configuration command to configure the IP address and subnet mask. Use the no  ip  address command to set the IP address and subnet mask to default values.

ip address ipaddress mask
no ip address

Syntax Description

ipaddress

IP address.

mask

Subnet mask.

Default

IP address and subnet mask both have the value 0.0.0.0.

Command Mode

Global configuration

Example

This example shows how to set the device IP address to 172.20.128.126 and the subnet mask to 255.255.255.0 on the specified interface.

hostname(config)# ip address 172.20.128.126 255.255.255.0
Related Commands

ip (default-gateway)
ip (domain-name)
ip (http port)
ip (http server)
ip (mgmt-vlan)
ip (name-server)
show (ip)

ip (default-gateway)

Use the ip default-gateway global configuration command to configure the default gateway. Use the no  ip  default-gateway command to delete a configured default gateway and set the gateway address to the default value.

ip default-gateway ip-address
no ip default-gateway

Syntax Description

ip-address

Gateway IP address.

Default

Gateway address has the value 0.0.0.0.

Command Mode

Global configuration

Example

This example shows how to set the default gateway address to 172.20.128.126.

hostname(config)# ip default-gateway 172.20.128.126
Related Commands

ip (address)
ip (domain-name)
ip (http port)
ip (http server)
ip (mgmt-vlan)
ip (name-server)
show (ip)

ip (domain-name)

Use the ip domain-name global configuration command to configure a domain name. Use the no  ip domain-name command to clear any configured domain name.

ip domain-name domain-name
no ip domain-name

Syntax Description

domain-name

A string between 1 and 63 characters that specifies the domain name.

Default

No domain name is configured.

Command Mode

Global configuration

Example

This example shows how to configure the domain name of the switch to your_company.com.

hostname(config)# ip domain-name your_company.com
Related Commands

ip (address)
ip (default-gateway)
ip (http port)
ip (http server)
ip (mgmt-vlan)
ip (name-server)
show (ip)

ip (http port)

Use the ip http port global configuration command to select a Transmmission Control Protocol (TCP) port on which the Hypertext Transfer Protocol (HTTP) server accepts connections. Use the no  ip http port command to select the default TCP port.

ip http port port-number
no ip http port

Syntax Description

port-number

TCP port number between 0 and 65535.

Default

TCP port 80.

Command Mode

Global configuration

Example

This example shows how to set the server to listen on TCP port 8080 for HTTP connections. With this (nondefault) setting, you must instruct your browser to connect to port 8080 rather than 80.

hostname(config)# ip http port 8080
Related Commands

ip (address)
ip (default-gateway)
ip (domain-name)
ip (http server)
ip (mgmt-vlan)
ip (name-server)
show (ip)

ip (http server)

Use the ip http server global configuration command to enable Hypertext Transfer Protocol (HTTP) server functions. Use the no  ip http server command to disable HTTP server functions.

ip http server
no ip http server

Syntax Description

This command has no additional arguments or keywords.

Default

HTTP server functions are enabled.

Command Mode

Global configuration

Example

This example shows how to disable HTTP server functions.

hostname(config)# no ip http server
Related Command

ip (address)
ip (default-gateway)
ip (http port)
ip (http port)
ip (mgmt-vlan)
ip (name-server)
show (ip)

ip (mgmt-vlan)

Use the ip mgmt-vlan global configuration command to configure a particular VLAN to be the management VLAN (the VLAN from which IP packets are accepted and processed). Use the no  ip mgmt-vlan command to set the default value as the management VLAN.

ip mgmt-vlan vlan-number
no ip mgmt-vlan

Syntax Description

vlan-number

VLAN number between 1 and 1005.

Default

VLAN 1 is the management VLAN.

Command Mode

Global configuration

Usage Guidelines

This command is only available when VLANs are enabled. IP traffic is received and processed only from the management VLAN.

Example

This example shows how to set VLAN 2 to be the management VLAN.

hostname(config)# ip mgmt-vlan 2
Related Commands

ip (address)
ip (default-gateway)
ip (domain-name)
ip (http port)
ip (http server)
ip (name-server)
show (ip)

ip (name-server)

Use the ip name-server global configuration command to configure a name server. Use the no  ip name-server command to clear any configured name server.

ip name-server name-server
no ip name-server name-server

Syntax Description

name-server

VLAN number between 1 and 1005.

Default

No name server address is configured.

Command Mode

Global configuration

Usage Guidelines

A maximum of two name servers can be configured. If both name servers are configured, one of them must be cleared using the no form of the command before it is replaced with another name server. If two name servers are already configured and the user tries to configure a third, an error message appears.

Example

This example shows how to configure 172.20.128.126 to be the name server of the switch.

hostname(config)# ip name-server 172.20.128.126
Related Commands

ip (address)
ip (default-gateway)
ip (domain-name)
ip (http port)
ip (http server)
ip (mgmt-vlan)
show (ip)

line (console)

Use the line console global configuration command to change to line-configuration mode.

line console

Syntax Description

This command has no additional arguments or keywords.

Command Mode

Global configuration

Example

This example shows how to change the command mode from global configuration to line configuration.

hostname(config)# line console
hostname(config-line)#
Related Commands

end
exit

login (tacacs)

Use the login tacacs global configuration command to enable the Cisco Terminal Access Controller Access Control System (TACACS+) for authenticating user logins. If login TACACS+ is enabled, the switch uses TACACS+ to authenticate all user logins through a console, Telnet, or Web interface. Use the no login tacacs command to disable TACACS+ authentication.

login tacacs
no login tacacs

Syntax Description

This command has no additional arguments or keywords.

Default

Disabled

Command Mode

Global configuration

Example

This command shows how to enable TACACS+ for login authentication.

hostname(config)# login tacacs
Related Commands

enable (use-tacacs)
show (tacacs)
tacacs-server (attempts)
tacacs-server (directed-request)
tacacs-server (host)
tacacs-server (key)
tacacs-server (last-resort)
tacacs-server (timeout)

mac-address-table (permanent)

Use the mac-address-table permanent global configuration command to associate a permanent unicast or multicast MAC address with a particular switched port interface (specified by type and module/port). Use the no  mac-address-table permanent command to delete a permanent MAC address.

mac-address-table permanent mac-address type module/port
no mac-address-table permanent mac-address type module/port

Syntax Description

mac-address

MAC unicast address.

type

Interface type: ethernet, fastethernet, fddi, line and atm, or port-channel.

module

Module interface number:

0 for fixed
1 or A for module A
2 or B for module B

port

Port interface number ranging from 1 to 28:

1 to 25 Ethernet (fixed)
26, 27 Fast Ethernet (fixed)
28 Port-channel

Default

No permanent addresses are assigned.

Command Mode

Global configuration

Usage Guidelines

Use the arguments module/port for switched ports and modules only. When deleting an address using the no mac-address-table permanent command, specify the interface on which the address resides.

If you delete an address that is not present in the address table, the following error message appears:

% Error: MAC address not found
Example

This example shows how to specify that packets with the multicast destination address 0140.C80A.2F07 should be forwarded on the interface fastethernet 0/27.

hostname(config)# mac-address-table permanent 0140.C80A.2F07 fastethernet 0/27
Related Commands

clear (mac-address-table)
mac-address-table (restricted static)
show (mac-address-table)

mac-address-table (restricted static)

Use the mac-address-table restricted static global configuration command to associate a restricted static address with a particular switched port interface (specified as type module/port). Use the no  mac-address-table restricted static command to delete a restricted static address.

mac-address-table restricted static mac-address type module/port src-if-list
no mac-address-table restricted static mac-address type module/port

Syntax Description

mac-address

MAC address.

type

Interface type: ethernet, fastethernet, fddi, line and atm, and port-channel.

module

Module interface number:

0 for fixed
1 or A for module 1
2 or B for module 2

port

Port interface number ranging from 1 to 28:

1 to 25 Ethernet (fixed)
26, 27 Fast Ethernet (fixed)
28 Port-channel

src-if-list

List of acceptable interfaces separated by spaces.

Default

No addresses are assigned.

Command Mode

Global configuration

Usage Guidelines

Use the arguments module/port for switched ports and modules only. Traffic to a restricted static address is only accepted from the interfaces specified in src-if-list.

Example

This example shows how a packet with MAC address of 0040.C80A.2F07 comes in on either interface ethernet 0/1 or ethernet 0/2 and is forwarded to the interface fastethernet 0/27.

hostname(config)# mac-address-table restricted static 0040.C80A.2F07 fastethernet 0/27 
    ethernet 0/1 ethernet 0/2 
Related Commands

clear (mac-address-table)
mac-address-table (permanent)
show (mac-address-table)

menu

Use the menu privileged Exec command to access the main menu console.

menu

Syntax Description

This command has no arguments or keywords.

Command Mode

Privileged Exec

Example

This example shows how to display the main menu console.

2820# menu

        Catalyst 2820 - Main Menu
     [C] Console Settings
     [S] System
     [N] Network Management
     [P] Port Configuration
     [A] Port Addressing
     [D] Port Statistics Detail
     [M] Monitoring
     [V] Virtual LAN
     [R] Multicast Registration
     [F] Firmware
     [I] RS-232 Interface
     [U] Usage Summaries
     [H] Help
     [K] Command Line
     [X] Exit Management Console
Enter Selection: 
Related Commands

None

modem (dialin)

Use the modem dialin line configuration command to enable auto-answer dial-in on a port. Use the no modem dialin command to disable dial-in.

modem dialin
no modem
dialin

Syntax Description

This command has no additional arguments or keywords.

Default

No modem dial-in is enabled.

Command Mode

Line configuration

Example

This example shows how to enable auto-answer dial-in.

hostname(config-line)# modem dialin
Related Commands

autobaud
databits
line (console)
modem (init-string)
parity
stopbits
terminal

modem (init-string)

Use the modem init-string line-configuration command to enable initialization string dial-in on a port. Use the no modem init-string command to disable initialization string dial-in.

modem init-string
no modem
init-string

Syntax Description

This command has no additional arguments or keywords.

Default

No initialization string is enabled.

Command Mode

Line configuration

Example

This example shows how to disable initialization string dial-in.

hostname(config-line)# no modem init-string
Related Commands

autobaud
databits
line (console)
modem (dialin)
parity
stopbits
terminal

monitor-port

Use the monitor-port global configuration command to enable port monitoring. Use the no  monitor-port command to disable monitoring.

monitor-port
no monitor-port

Syntax Description

This command has no arguments or keywords.

Default

No ports are monitored.

Command Mode

Global configuration

Usage Guidelines

Before you enable port monitoring, ensure that your capture list has one or more ports listed and a monitor port assigned. To add ports to the capture list, use the monitor-port monitored command. To assign a monitor port, use the monitor-port port command.

Example

This example shows how to enable port monitoring.

hostname(config)# monitor-port
Related Commands

monitor-port (port)
show (port monitor)

monitor-port (monitored)

Use the monitor-port monitored global configuration command to add ports to the monitoring capture list. Use the no monitor-port monitored command to delete ports from the list.

monitor-port monitored module/port
no monitor-port monitored [module/port]

Syntax Description

module

Interface number from 0 to 2.

port

Port interface number ranging from 1 to 27:

1 to 25 Ethernet (fixed)
26, 27 Fast Ethernet (fixed)

Default

No ports are monitored.

Command Mode

Global configuration

Usage Guidelines

Use the arguments module/port for switched ports and modules only. If you do not specify the list of ports to add or delete in the no command form, all ports are deleted. If the module/port argument is not specified, the command applies to all ports.

Example

This example shows how to add port 26 to the capture list.

hostname(config)# monitor-port monitored 0/26

This example shows how to delete port 2 from the capture list.

hostname(config)# no monitor-port monitored 0/2

This example shows how to delete all ports from the capture list.

hostname(config)# no monitor-port monitored
Related Commands

monitor-port
monitor-port (port)

monitor-port (port)

Use the monitor-port port global configuration command to specify the port to which monitored frames are sent. Use the no  monitor-port port command to clear the monitor port and disable monitoring.

monitor-port port module/port
no monitor-port port

Syntax Description

module

Interface number between 0 and 2.

port

Port interface number ranging from 1 to 27:

1 to 25 Ethernet (fixed)
26, 27 Fast Ethernet (fixed)

Default

No ports are monitored.

Command Mode

Global configuration

Usage Guidelines

Use the arguments module/port for switched ports and modules only. One or more ports must be listed in the port capture list for frame monitoring to occur.

Example

This example shows how to set port 0/1 to receive monitored frames.

hostname(config)# monitor-port port 0/1
Related Commands

monitor-port
monitor-port (monitored)

multicast-store-and-forward

Use the multicast-store-and-forward global configuration command to set multicast traffic forwarding to store-and-forward mode. Use the no multicast-store-and-forward command to set multicast traffic forwarding to the method specified by the switching-mode command.

multicast-store-and-forward
no multicast-store-and-forward

Syntax Description

This command has no arguments or keywords.

Default

Multicast forwarding is disabled.

Command Mode

Global configuration

Example

This example shows how to set the multicast traffic forwarding to store-and-forward.

hostname(config)# multicast-store-and-forward

This example shows how to set the multicast traffic forwarding to the method specified by the switching-mode command.

hostname(config)# no multicast-store-and-forward
Related Command

switching-mode

network-port

Use the network-port global configuration command to set a network port. Use the no  network-port command to clear a network port.

network-port module/port
no network-port

Syntax Description

module

Module number from 0 to 2.

port

Port number from 1 to 27.

Default

A network port does not exist.

Command Mode

Global configuration

Usage Guidelines

Use the arguments module/port for switched ports and modules only. When you configure a port as a network port, the following restrictions apply:

Example

The following example shows how to set port 0/2 as a network port.

hostname(config)# network-port 0/2
Related Command

show (port system)

pagp-port-priority

Use the pagp-port-priority interface configuration command to specify the Port Aggregation Protocol (PAgP) hot-standby priority for a single Fast Ethernet port.

pagp-port-priority priority

Syntax Description

priority

Number from 0 to 255.

Default

The default priority is 128.

Command Mode

Interface configuration

Usage Guidelines

This command has the following restrictions:

Example

The following example shows how to set the PAgP priority for Fast Ethernet port A to 100:

hostname(config)# interface fastethernet 0/26
hostname(config-if)# pagp-port-priority 100
Related Commands

port-channel (mode)
show (interfaces)
port-channel (preserve-order)
port-channel template-port

parity

Use the parity line-configuration command to set the parity of the port. Use the no  parity command to disable parity for the port.

parity {none | odd | even | mark | space}
no parity

Syntax Description

none

No parity.

odd

Odd parity.

even

Even parity.

mark

Mark parity.

space

Space parity.

Default

The default is no parity.

Command Mode

Line configuration

Example

The following example shows how to set the parity of an Ethernet port to odd:

hostname(config-line)# parity odd
Related Commands

autobaud
databits
line (console)
modem (dialin)
show (line)
stopbits
terminal

ping

Use the ping user Exec command to send an ICMP echo message (ping) to the specified IP address or host name.

ping {ip-address | hostname}

Syntax Description

ip-address

Host IP address.

hostname

Host name.

Default

This command has no default value.

Command Mode

User Exec

Usage Guidelines

If you specify a host name rather than an IP address, the configured name server (which is configured using the ip name server command) resolves the host name to the IP address.

Example

The following example shows how to ping the host named penguins:

> ping penguins

Translating "penguins"...domain server (171.68.10.70) [OK]
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 171.69.71.25, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/6 ms 
Related Commands

ip (address)
ip (default-gateway)
ip (domain-name)
ip (mgmt-vlan)
ip (name-server)
port-channel (mode)
port-channel (preserve-order)
port-channel template-port
show (interfaces)
show (ip)

port (block)

Use the port block interface configuration command to block the flooding of unknown multicast or unicast packets. Use the no port block command to enable the flooding of unknown multicast or unicast packets.

port block {multicast | unicast}
no port block {multicast | unicast}

Syntax Description

multicast

Unknown multicast addresses.

unicast

Unknown unicast addresses.

Default

Flooding is enabled.

Command Mode

Interface configuration

Examples

The following example shows how to block the flooding of unknown multicast addresses:

hostname(config-if)# port block multicast

The following example shows how to allow the flooding of unknown unicast addresses:

hostname(config-if)# no port block unicast
Related Commands

interface
show (interfaces)
show (port block)

port-channel (mode)

Use the port-channel mode global configuration command to select the way in which two Fast Ethernet ports aggregate using Port Aggregation Protocol (PAgP) to form a Fast EtherChannel link. Use the no port-channel mode command to disable Fast EtherChannel links.

port-channel mode [on | auto | desirable | off]
no port-channel mode

Syntax Description

on

Forces the port to aggregate without negotiation.

auto

Port responds to PAgP packets it receives but does not initiate PAgP packet negotiation.

desirable

Port initiates negotiations with other ports by sending PAgP packets.

off

Prevents the port from aggregating without negotiation.

Default

The port is prevented from aggregating without negotiation (off).

Command Mode

Global configuration

Usage Guidelines

When a Fast EtherChannel link is formed, the port-channel interface is enabled. The port channel remains enabled until both ports lose the link. In the case of port-channel auto or desirable mode, when a port-channel member port detects a partner port that is misconfigured, disabled, or is not bidirectional, the port-channel member port goes down.

Both the auto and desirable modes allow ports to negotiate with connected ports to determine if they can form a channel based on criteria such as trunking state, VLAN numbers, and so on.

This command is not functional when bridge groups are enabled.

Example

The following example shows how to create a Fast EtherChannel when the PAgP status of connecting devices is uncertain:

hostname(config)# port-channel mode desirable

The following example shows how to create a channel interface and enable a Fast EtherChannel with PAgP disabled.

hostname(config)# port-channel mode on
Related Commands

pagp-port-priority
port-channel (preserve-order)
port-channel template-port
show (interfaces)

port-channel (preserve-order)

Use the port-channel preserve-order global configuration command to preserve the frame transmission order on the channel interface. Use the no  port-channel preserve-order command to allow frame transmission misordering on the channel interface.

port-channel preserve-order
no port-channel preserve-order

Syntax Description

This command has no additional arguments or keywords.

Default

The default is no frame ordering.

Command Mode

Global configuration

Usage Guidelines

The no  port-channel preserve-order command allows frame transmission misordering for maximum load balancing.

This command is not functional when bridge groups are enabled.

Example

The following example shows how to preserve frame transmission order on the channel interface:

hostname(config)# port-channel preserve-order
Related Commands

port-channel (mode)
show (interfaces)

port-channel template-port

Use the port-channel template-port global configuration command to specify a Fast Ethernet port after which other grouped member ports are modeled.

port-channel template-port template-port

Syntax Description

template-port

For Catalyst 2820 switches, fastethernet 1 or fastethernet 2;
For Catalyst 1900 switches, fastethernet 0/26 or fastethernet 0/27.

Defaults

Fast Ethernet port 1 for the Catalyst 2820 series switches.
Fast Ethernet port 0/26 for the Catalyst 1900 series switches.

Command Mode

Global configuration

Usage Guidelines

The configuration parameters for which the specified Fast Ethernet port serves as a model or template are as follows:

The configuration parameters remain the same for all member ports after aggregation. After the group is created, any change to the parameters of any member port or port channel applies to all other ports in the group.

This command is available only when bridge groups are enabled.

Example

The following example shows how to specify Fast Ethernet port 27 as the template port for member ports configuration:

hostname(config)# port-channel template-port fastethernet 0/27
Related Commands

port-channel (mode)
show (interfaces)

port (secure)

Use the port secure interface configuration command to enable addressing security. Use the no port secure command to disable addressing security or set the maximum number of addresses allowed on the interface to the default value.

port secure [max-mac-count count]
no port secure [max-mac-count]

Syntax Description

max-mac-count

Maximum number of addresses allowed on port.

count

Number from 1 to 132.

Default

The default is 132.

Command Mode

Interface configuration

Example

The following example shows how to set the maximum MAC address count to 100.

hostname(config-if)# port secure max-mac-count 100

The following example shows how to disable port security.

hostname(config-if)# no port secure

The following example shows how to set the MAC address count maximum to the default 132.

hostname(config-if)# no port secure max-mac-count
Related Commands

interface
port (block)
show (interfaces)
show (mac-address-table security)

reload

Use the reload privileged Exec command to reset the switch or module.

reload [type module]

Syntax Description

type

Interface type: fddi and atm.

module

Interface number of a module:
1 or A for module 1
2 or B for module 2

Default

The entire switch or module is reset (rather than a specific type).

Command Mode

Privileged Exec

Usage Guidelines

After you enter this command, the system displays the following message:

Reset system, [Y]es or [N]o ?

Press Y or N as desired.

After the reset, the switch or module retains all configured system parameters and static addresses and removes all dynamic addresses.

Example

The following example shows how to reset the entire switch:

hostname# reload

The following example shows how to reset the FDDI module in slot A.

hostname# reload fddi A
Related Command

delete (nvram)

rip

Use the rip global configuration command to enable the automatic discovery of IP gateways by running the Routing Information Protocol (RIP) listener. Use the no  rip command to disable the RIP listener.

rip
no rip

Syntax Description

This command has no arguments or keywords.

Default

The RIP listener is enabled.

Command Mode

Global configuration

Example

The following example shows how to disable the RIP listener:

hostname(config)# no rip
Related Command

ip (default-gateway)

service (config)

Use the service config global configuration command to enable automatic download of the switch configuration file from aTrivial File Transfer Protocol (TFTP) host during power up. Use the no  service config command to disable auto configuration of the switch.

service config
no service config

Syntax Description

This command has no additional arguments or keywords.

Default

Auto configuration is disabled.

Command Mode

Global configuration

Usage Guidelines

Note If your switch is set up for auto configuration through Dynamic Host Configuration Protocol (DHCP), the DHCP auto configuration overrides the no  service config command.
Example

The following example shows how to enable auto configuration:

hostname(config)# service config
Related Command

show (running-config)

session

Use the session user Exec command to open a session to an ATM module with an independent operating system.

session {number}

Syntax Description

number

Module slot number:
A or 1 for slot A
B or 2 for slot B

Default

This command has no default value.

Command Mode

User Exec

Example

The following example shows how to open a session to the ATM module installed in slot B of the switch:

switch> session B
Related Commands

None

show (bridge-group)

Use the show bridge-group privileged Exec command to display the current bridge group configuration and port membership.

show bridge-group

Syntax Description

This command has no additional arguments or keywords.

Default

This command has no default value.

Command Mode

Privileged Exec

Usage Guidelines

This command is available only when bridge groups are enabled.

Example

The following example shows how to display the current bridge-group configuration and port membership:

hostname# show bridge-group
Allow overlapping bridge-groups: Disabled
Bridge Group                                          Member Ports
------------------------------------------------------------------------------------
  1                                                            2, 4, 5, 9-20
  2                                                            21-25
  3                                                            1, 3, 6, 7, 8
  4                                                            A, B
Related Commands

bridge (forwarding-time)
bridge (hello-time)
bridge (max-age)
bridge (priority)
bridge-group
bridge-group (allow-overlap)
bridge-group (enable)
show (spantree bridge-group)
spantree (bridge-group)

show (cdp interface)

Use the show cdp interface user Exec command to display CDP status and configuration information for a switched port or module.

show cdp interface [type module/port]

Syntax Description

type

Interface type. Valid values are ethernet, fastethernet, fddi, line and atm, and port-channel.

module

Module interface number:
0 for fixed
1 or A for module A
2 or B for module B

port

Port number:
1 to 25 Ethernet interface number (fixed)
26, 27 Fast Ethernet interface number (fixed)

Default

This command has no default value.

Command Mode

User Exec

Usage Guidelines

If you do not specify the type and module/port options, CDP configuration on all interfaces is displayed.

Example

The following example shows how to display the CDP configuration on all interfaces.

> show cdp interface 
Ethernet 0/1  : Cdp enabled
Ethernet 0/2  : Cdp enabled
Ethernet 0/3  : Cdp enabled
Ethernet 0/4  : Cdp enabled
Ethernet 0/5  : Cdp enabled
Ethernet 0/6  : Cdp enabled
Ethernet 0/7  : Cdp enabled
Ethernet 0/8  : Cdp enabled
Ethernet 0/9  : Cdp enabled
Ethernet 0/10  : Cdp enabled
Ethernet 0/11  : Cdp enabled
Ethernet 0/12  : Cdp enabled
Ethernet 0/13  : Cdp enabled
Ethernet 0/14  : Cdp enabled
Ethernet 0/15  : Cdp enabled
Ethernet 0/16  : Cdp enabled
Ethernet 0/17  : Cdp enabled
Ethernet 0/18  : Cdp enabled
Ethernet 0/19  : Cdp enabled
Ethernet 0/20  : Cdp enabled
Ethernet 0/21  : Cdp enabled
Ethernet 0/22  : Cdp enabled
Ethernet 0/23  : Cdp enabled
Ethernet 0/24  : Cdp enabled
Ethernet 0/25  : Cdp enabled
FastEthernet 0/26  : Cdp enabled
FastEthernet 0/27  : Cdp enabled
Related Commands

cdp (enable)
cgmp (hold-time)
cdp (timer)
show (bridge-group)
show (cdp neighbors)

show (cdp neighbors)

Use the show cdp neighbors user Exec command to display information on network neighbors the switch discovers using Cisco Discovery Protocol (CDP).

show cdp neighbors [type module/port] [detail]

Syntax Description

type

Interface type. Valid values are ethernet, fastethernet, fddi, line and atm, and port-channel.

module

Module interface number:
0 for fixed
1 or A for module 1
2 or B for module 2

port

Port number:
1 to 25 Ethernet interface number (fixed)
26, 27 Fast Ethernet interface number (fixed)

detail

List details about network neighbors including device ID, entry address, platform, capabilities, remote interface, and local interface.

Default

This command has no default value.

Command Mode

User Exec

Usage Guidelines

If you do not specify an option, the switch displays discovered neighbors from all interfaces. If you specify the type and module/port of an interface, the discovered neighbors from that interface appears.

Example

The following example shows how to display all discovered switch neighbors using CDP.

hostname# show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater
Device ID                          Local Interface    Holdtime    Capability    Platform    Port ID
Molehill_Alpha#2.cis        Eth 0/7                    40                H r              216                  Eth 0
boba-malibu.cisco.co        Eth 0/7                    163                                  Malibu MAL    Fas 0/1
scotte-pb.cisco.com          Eth 0/7                    152              S                  Cisco WS-C    Fas 0/2
malibu-cons.cisco.co        Eth 0/7                    164              R                  2511                Eth 0
rheaton-daytona.cisc        Eth 0/7                    136                                  Malibu MAL    Fas 0/2
scotte-daytona.cisco        Eth 0/7                    147              S                  Cisco WS-C    Fas 0/2
pheller-malibu.cisco        Eth 0/2                    149                                  Malibu MAL    Fas 0/2
tacoma-alpha-2.00E01        Eth 0/7                    11               T r              316                  R
rheaton-2500.cisco.c        Eth 0/7                    131              R                  2511                Eth 0
boba-daytona.cisco.c        Eth 0/7                    169                                  Malibu MAL    Fas 0/6
tacoma-alpha-2.00E01        Eth 0/7                    6                  T r              316                  R
tacoma-alpha-2.00E01        Eth 0/7                    0                  T r              316                  R
tacoma-alpha-2.00E01        Eth 0/7                    1                 T r              316                  R 

The following example shows how to display discovered switch neighbors for Ethernet port 9 in detail.

hostname# show cdp neighbors ethernet 0/9 detail
Device ID :  00C01D810DF3
Entry Address :0.0.0.0
Platform : cisco 1900
Capabilities :  Trans Bridge Switch
Remote Interface : 3
Local Interface : Ethernet 0/9
Related Commands

cdp (enable)
cdp (holdtime)
cdp (timer)
show (bridge-group)
show (cdp interface)

show (cgmp)

Use the show cgmp privileged Exec command to display information gathered from Cisco Group Management Protocol (CGMP).

show cgmp

Syntax Description

This command has no additional arguments or keywords.

Default

This command has no default value.

Command Mode

Privileged Exec

Example

The following example shows how to display all information gathered from CGMP:

hostname# show cgmp
VLAN            MAC address            Interface(s)
----            ------------          ------------
1                  0100.5E7F.0001      Eth0/5, fa0/26, fa0/27
1                  0100.5E01.0101      Eth0/12, fa0/26, fa0/27
2                  0100.5E01.0101      Eth0/3, fa0/26
2                  0100.5E7F.0001      Eth0/1, fa0/26

The VLAN column of this display does not appear in bridge-group mode.

Related Commands

cgmp
cgmp (hold-time)
cgmp (remove)
show (cgmp)

show (history)

Use the show history user Exec command to display the Exec commands used in this session.

show history

Syntax Description

This command has no additional arguments or keywords.

Default

This command has no default value.

Command Mode

User Exec

Usage Guidelines

The display does not include configuration commands.

Example

The following example shows how to display the Exec commands used in the current session:

> show history
ena
end
disab
show hi 
Related Command

show (running-config)

show (interfaces)

Use the show interfaces privileged Exec command to display statistics and status for all or specified interfaces.

show interfaces [type module/port] [basic | secondary]

Syntax Description

type

Interface type:
ethernet Displays statistics and status for Ethernet interfaces.
fastethernet Displays statistics and status for Fast Ethernet interfaces.
fddi Displays statistics and status for FDDI interfaces.
atm Displays statistics and status for ATM interfaces.
port-channel Displays statistics and status for port-channel interfaces.

module

Module interface number:
0 for fixed
1 or A for module A
2 or B for module B

port

Port number:
1 to 25 Ethernet interface number (fixed)
26, 27 Fast Ethernet interface number (fixed)

basic

Basic FDDI settings.

secondary

Secondary FDDI settings.

Default

If you do not specify a type or a module/port, statistics and status for all interfaces appear. Use the basic and secondary arguments only with FDDI ports.

Command Mode

Privileged Exec

Usage Guidelines

The output to this command varies depending on the network for which an interface has been configured.

Examples

The following example shows how to display statistics and status for all interfaces:

hostname# show interfaces

The following example shows how to display statistics and status for Ethernet port 1.

hostname# show interfaces ethernet 0/1
Ethernet 0/1 is Suspended-no-linkbeat
Hardware is Built-in 10Base-T
Address is 00E0.1EA2.FBC1
MTU 1500 bytes, BW 10000 Kbits
802.1d STP State:  Blocking     Forward Transitions:  2
Port monitoring: Disabled
Unknown unicast flooding: Disabled
Unregistered multicast flooding: Disabled
Description: ests
Duplex setting: Full duplex
Back pressure: Disabled

    Receive Statistics                     Transmit Statistics
-------------------------------------  -------------------------------------
Total good frames                   0  Total frames                        0
Total octets                        0  Total octets                        0
Broadcast/multicast frames          0  Broadcast/multicast frames          0
Broadcast/multicast octets          0  Broadcast/multicast octets          0
Good frames forwarded               0  Deferrals                           0
Frames filtered                     0  Single collisions                   0
Runt frames                         0  Multiple collisions                 0
No buffer discards                  0  Excessive collisions                0
                                       Queue full discards                 0
Errors:                                Errors:
  FCS errors                        0    Late collisions                   0
  Alignment errors                  0    Excessive deferrals               0
  Giant frames                      0    Jabber errors                     0
  Address violations                0    Other transmit errors             0

The following example shows how to display statistics and status for Fast Ethernet port A.

hostname# show interfaces fastethernet 0/26

The following is a sample display for a single-port 100BaseTX in trunk mode. Trunk-related information does not display if the interface is not in trunk mode.

FastEthernet0/26 is enabled
Hardware is built-in 100BaseTX
Address is 0053.4500.0201 
MTU 1500 bytes, BW 100000 Kbit
802.1d STP State:  Forwarding, Forward Transitions:  1
Broadcast forwarding: Blocked due broadcast storm
Description: port-A
Duplex/Flow Control setting: full duplex with flow control
Auto-negotiation status: auto-negotiate
Enhanced congestion control: disabled 
Receive Statistics                     Transmit Statistics
-------------------------------------  -------------------------------------
Total good frames               48588  Total frames                    35638
Total octets                  4663880  Total octets                  2696516
Broadcast/multicast frames      37004  Broadcast/multicast frames      33261
Broadcast/multicast octets    3256467  Broadcast/multicast octets    2183516
Good frames forwarded           48567  Deferrals                           0
Frames filtered                    21  Single collisions                   0
Runt frames                         0  Multiple collisions                 0
No buffer discards                  0  Excessive collisions                                                 
                                    0
                                       Queue full discards                 0
Errors:                                Errors:
  FCS errors                        0    Late collisions                   0
  Alignment errors                  0    Excessive deferrals               0
  Giant frames                      0    Jabber errors                     0
  Address violations                0    Other transmit errors             0 

The following example shows how to display statistics and status for FDDI module 1:

hostname# show interfaces fddi 1
fddi             1 is suspended-ring-down
Hardware is FDDI Module (Fiber DAS Model), Version 00
Module Description: Dual Attach Station, Ring status: Not operational
Address is 0053.4500.0201             
MTU 4352 bytes, BW 100000 Kbit
802.1d STP State:  N/A, Forward Transitions:  0
Broadcast storm control: blocked
Description:
Novell SNAP frame translation: Automatic
Unmatched SNAP frame destination: All
Receive Statistics                     Transmit Statistics
-------------------------------------  -------------------------------------
Good FDDI frames                    0  Good FDDI frames                  256
Good FDDI octets                    0  Good FDDI octets                19716
No buffer discards                  0  No buffer discards                  0
IP frames fragmented                0  Ring down discards                  0
Frames filtered                     0  Queue full discards                 0
Good frames forwarded               0
Errors:
  FCS Error                         0
  Invalid data length               0
  Error flag set                    0
  Bad IP header                     0
  Other receive errors              0
  Address violations                0 

The following example shows how to display basic FDDI settings for FDDI module 1:

hostname# show interfaces fddi 1 basic

------------------------ MAC and SMT Information --------------------------
 SMT version              2    Upstream neighbor     00-00-F8-00-00-00
 MIB version              1    Station address       00-00-00-C0-1D-F4-76-65
 Number of MACs           1    Downstream neighbor   00-00-F8-00-00-00
 Non master ports         2    Optical bypass        Not present
 ECM state               In    Attachment state      Isolated
 ------Port Information------- ------A Port------    ------B Port------
 Connection policy (rejects)   None                  None
 Neighbor type                 None                  None
 Current path                  Isolated              Isolated
 Available paths               Primary+Secondary     Primary+Secondary
 PMD class                     Multimode             Multimode
 PCM state                     Connect               Connect
 Link error alarm activated    False                 False
 Link confidence test failures 0                     0
 Link error monitor rejections 0                     0
 Aggregate link error count    0                     0 

The following example shows how to display secondary FDDI settings for FDDI module 2.

hostname# show interfaces fddi 2 secondary
Notification timer value: 30 second(s)
Use authorization string: Disabled
Authorization string:

                        ------------MAC and SMT Information-----------
     Remote disconnect flag                          False
     Station path status                             Separated
     Requested token rotation time                   164986880 ns
     Negotiated token rotation time                  164986880 ns
     Old upstream neighbor                           00-00-F8-00-00-00
     Old downstream neighbor                         00-00-F8-00-00-00
     MAC's downstream port type                      None
     Frame error flag                                False
     Frame processing functions                      fs_repeating
     MAC's available paths                                            Primary+Secondary

The following example shows how to display status information on ATM module 1:

hostname# show interfaces atm 1
Atm 1 is suspended-ATM-LANE-down
Hardware is ATM 155 UTP, Version 02
  Module Description: Category 5 UTP
Address is 0053.4500.0201
ATM Network Status:  Not operational 
802.1d STP State:  N/A, Forward Transitions:  0
Broadcast storm control: blocked
Description/name of port:

Receive Statistics                     Transmit Statistics
-------------------------------------  -------------------------------------
Good AAL5 frames                    0  Good AAL5 frames                    0
Good ATM cells                      0  Good ATM cells                      0
Broadcast/multicast frames          0  Broadcast/multicast frames          0
Good frames forwarded               0  Queue full discards                 0
Frames filtered                     0
Runt frames                         0
No buffer discards                  0
Other discards                      0
Errors:
    CRC errors                      0
    Cell HEC errors                 0
    Giant frames                    0
    Address violations              0

The following example shows how to display statistics and status for a port channel. The statistics for each port are the sum of all packets that went through all member ports in the channel.

hostname# show interfaces port-channel
PortChannel is Enabled
802.1d STP State:  Forwarding     Forward Transitions:  1
Port-channel mode: auto, preserve-order: Disabled
Port parameters template port: A
Active port: A
Port Member Priority Cap.  Partner            Partner Partner  Partner
                           Device-id          Port-id Priority Cap.
-----------------------------------------------------------------------
A    Yes    128      1     00-E0-1E-7E-C2-C0  A       128      3
B    Yes    128      1     00-E0-1E-7E-C2-C0  B       128      3

    Receive Statistics                     Transmit Statistics
-------------------------------------  -------------------------------------
Total good frames                 139  Total frames                     1789
Total octets                    13038  Total octets                   142757
Broadcast/multicast frames        138  Broadcast/multicast frames       1763
Broadcast/multicast octets      12936  Broadcast/multicast octets     140191
Good frames forwarded             138  Deferrals                           0
Frames filtered                     1  Single collisions                   0
Runt frames                         0  Multiple collisions                 0
No buffer discards                  0  Excessive collisions                0
                                       Queue full discards                 0
Errors:                                Errors:
  FCS errors                        0    Late collisions                   0
  Alignment errors                  0    Excessive deferrals               0
  Giant frames                      0    Jabber errors                     0
  Address violations                0    Other transmit errors             0 
Related Commands

back-pressure
description
duplex
fddi (authorization)
fddi (auth-string)
fddi (novell-snap-translation)
fddi (unmatched-snap-translation)
interface


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