Configuring Ethernet, Fast Ethernet, and Gigabit Ethernet Switching

This chapter describes how to use the command-line interface (CLI) to configure Ethernet, Fast Ethernet, and Gigabit Ethernet switching on the Catalyst 5000 series switches. The configuration tasks in this chapter apply to Ethernet, Fast Ethernet, and Gigabit Ethernet switching modules, as well as to the Fast Ethernet and Gigabit Ethernet uplink ports on the supervisor engine.

Note For complete syntax and usage information for the commands used in this chapter, refer to the Catalyst 5000 Series Command Reference publication.

This chapter consists of these sections:

Understanding How Ethernet Works

The Catalyst 5000 series switch supports simultaneous, parallel conversations between Ethernet segments. Switched connections between Ethernet segments last only for the duration of the packet. New connections can be made between different segments for the next packet.

The Catalyst 5000 series switch solves congestion problems caused by high bandwidth devices and a large number of users by assigning each device (for example, a server) to its own 10- or 100-Mbps segment. Because each Ethernet port on the Catalyst 5000 series switch represents a separate Ethernet segment, servers in a properly configured switched environment achieve full access to the bandwidth.

Because the major bottleneck in Ethernet networks is usually due to collisions, an effective solution is full-duplex communication, an option for each port on the Catalyst 5000 series switch. Normally, Ethernet operates in half-duplex mode, which means that stations can either receive or transmit. In full-duplex mode, two stations can transmit and receive at the same time. When packets can flow in both directions simultaneously, effective Ethernet bandwidth doubles from 10 Mbps to 20 Mbps for 10BaseT ports and to 200 Mbps for Fast Ethernet ports.

Switching Frames Between Segments

Each Ethernet port on the Catalyst 5000 series switch can connect to a single workstation or server, or to a hub through which workstations or servers connect to the network.

Ports on a typical Ethernet hub all connect to a common backplane within the hub, and the bandwidth of the network is shared by all devices attached to the hub. If two stations establish a session that uses a significant level of bandwidth, the network performance of all other stations attached to the hub is degraded.

To reduce degradation, the Catalyst 5000 series switch treats each port as an individual segment. When stations on different ports need to communicate, the Catalyst 5000 series switch forwards frames from one port to the other at wire speed to ensure that each session receives the full 10-Mbps bandwidth.

To switch frames between ports efficiently, the Catalyst 5000 series switch maintains an address table. When a frame enters the Catalyst 5000 series switch, it associates the media-access control (MAC) address of the sending station with the port on which it was received.

Building the Address Table

The Catalyst 5000 series switch builds the address table by using the source address of the frames received. When the switch receives a frame for a destination address not yet listed in its address table, it floods the frame to all ports of the same virtual LAN (VLAN) except the port that received the frame. When the destination station replies, the switch adds its relevant source address and port ID to the address table. The Catalyst 5000 series switch then forwards subsequent frames to a single port without flooding to all ports.

The address table can store at least 16,000 address entries without flooding any entries. The Catalyst 5000 series switch uses an aging mechanism, defined by a configurable aging timer, so if an address remains inactive for a specified number of seconds, it is removed from the address table.

Default Ethernet, Fast Ethernet, and Gigabit Ethernet Configuration

Table 4-1 shows the Ethernet, Fast Ethernet, and Gigabit Ethernet default configuration.

Table 4-1: Ethernet, Fast Ethernet, and Gigabit Ethernet Default Configuration
Feature Default Value

Port enable state

All ports are enabled

Port name

None

Port priority

Normal

Duplex mode

Half-duplex for 10-Mbps Ethernet ports

Autonegotiate speed and duplex for 10/100-Mbps Fast Ethernet ports

Autonegotiate duplex for 100-Mbps Fast Ethernet ports

Full-duplex for 1000-Mbps Gigabit Ethernet ports

Flow control (Gigabit Ethernet only)

Flow control set to off for receive (Rx) and desired for transmit (Tx)

Spanning-Tree Protocol

Enabled for VLAN 1

Native VLAN

VLAN 1

Port VLAN cost

Port VLAN cost of 100 for 10-Mbps Ethernet ports

Port VLAN cost of 19 for 10/100-Mbps Fast Ethernet ports

Port VLAN cost of 19 for 100-Mbps Fast Ethernet ports

Port VLAN cost of 4 for 1000-Mbps Gigabit Ethernet ports

Fast EtherChannel

Disabled on all Fast Ethernet ports

**Table 4-1: Ethernet, Fast Ethernet, and Gigabit Ethernet Default Configuration**
Feature	Default Value
Port enable state	All ports are enabled
Port name	None
Port priority	Normal
Duplex mode	Half-duplex for 10-Mbps Ethernet ports Autonegotiate speed and duplex for 10/100-Mbps Fast Ethernet ports Autonegotiate duplex for 100-Mbps Fast Ethernet ports Full-duplex for 1000-Mbps Gigabit Ethernet ports
Flow control (Gigabit Ethernet only)	Flow control set to off for receive (Rx) and desired for transmit (Tx)
Spanning-Tree Protocol	Enabled for VLAN 1
Native VLAN	VLAN 1
Port VLAN cost	Port VLAN cost of 100 for 10-Mbps Ethernet ports Port VLAN cost of 19 for 10/100-Mbps Fast Ethernet ports Port VLAN cost of 19 for 100-Mbps Fast Ethernet ports Port VLAN cost of 4 for 1000-Mbps Gigabit Ethernet ports
Fast EtherChannel	Disabled on all Fast Ethernet ports

Setting the Port Configuration

These sections describe how to configure Ethernet, Fast Ethernet, and Gigabit Ethernet switching on the Catalyst 5000 series switches:

Setting the Port Name

You can assign names to the ports on Ethernet, Fast Ethernet, and Gigabit Ethernet modules to facilitate switch administration.

To assign a name to a port, perform this task in privileged mode:

Task Command

Step 1 Assign a name to a port.

set port name mod_num/port_num [name_string]

Step 2 Verify that the port name is configured.

show port [mod_num[/port_num]]

Task	Command
Step 1 Assign a name to a port.	set port name mod_num/port_num [name_string]
Step 2 Verify that the port name is configured.	show port [mod_num[/port_num]]

This example shows how to set the name for ports 1/1 and 1/2 and how to verify that the port names are configured correctly:

Console> (enable) set port name 1/1 Router Connection

Port 1/1 name set.
Console> (enable) set port name 1/2 Server Link

Port 1/2 name set.
Console> (enable) show port 1

Port  Name               Status     Vlan       Level  Duplex Speed Type
----- ------------------ ---------- ---------- ------ ------ ----- ------------
 1/1  Router Connection  connected  trunk      normal   half   100 100BaseTX
 1/2  Server Link        connected  trunk      normal   half   100 100BaseTX
<...output truncated...>
Last-Time-Cleared
--------------------------
Tue Jun 16 1998, 16:25:57
Console> (enable)

Setting the Port Priority Level

You can configure the priority level of each port. When ports request access to the switching bus simultaneously, the Catalyst 5000 series switch uses the port priority level to determine the order in which ports are given access.

To set the port priority level, perform this task in privileged mode:

Task Command

Step 1 Configure the priority level for a port.

set port level mod_num/port_num {normal | high}

Step 2 Verify that the port priority level is configured correctly.

show port [mod_num[/port_num]]

Task	Command
Step 1 Configure the priority level for a port.	set port level mod_num/port_num {normal \| high}
Step 2 Verify that the port priority level is configured correctly.	show port [mod_num[/port_num]]

This example shows how to set the port priority level to high for port 1/1 and verify that the port priority is configured correctly:

Console> (enable) set port level 1/1 high

Port 1/1 level set to high.
Console> (enable) show port 1

Port  Name               Status     Vlan       Level  Duplex Speed Type
----- ------------------ ---------- ---------- ------ ------ ----- ------------
 1/1  Router Connection  connected  trunk      high     half   100 100BaseTX
 1/2  Server Link        connected  trunk      normal   half   100 100BaseTX
<...output truncated...>
Last-Time-Cleared
--------------------------
Tue Jun 16 1998, 16:25:57
Console> (enable)

Setting the Port Speed

You can configure the port speed on 10/100-Mbps Fast Ethernet modules. Use the auto keyword to have the port autonegotiate speed and duplex mode with the neighboring port.

Note If the port speed is set to auto on a 10/100-Mbps Fast Ethernet port, both speed and duplex are autonegotiated.

To set the port speed for a 10/100-Mbps port, perform this task in privileged mode:

Task Command

Step 1 Set the port speed of a 10/100-Mbps Fast Ethernet port.

set port speed mod num/port num {10 | 100 | auto}

Step 2 Verify that the speed of the port is configured correctly.

show port [mod_num[/port_num]]

Task	Command
Step 1 Set the port speed of a 10/100-Mbps Fast Ethernet port.	set port speed mod num/port num {10 \| 100 \| auto}
Step 2 Verify that the speed of the port is configured correctly.	show port [mod_num[/port_num]]

This example shows how to set the port speed to 100 Mbps on port 2/2:

Console> (enable) set port speed 2/2 100

Port 2/2 speed set to 100 Mbps.
Console> (enable)

This example shows how to make port 2/1 autonegotiate speed and duplex with the neighbor port:

Console> (enable) set port speed 2/1 auto

Port 2/1 speed set to auto-sensing mode.
Console> (enable)

Setting the Port Duplex Mode

You can set the port duplex mode to full or half duplex for Ethernet and Fast Ethernet ports.

Note The Gigabit Ethernet switching module (WS-X5403) and the Gigabit uplink module (WS-U5534-GESX) support full-duplex only. You cannot change the duplex mode on these modules.

Note If the port speed is set to auto on a 10/100-Mbps Fast Ethernet port, both speed and duplex are autonegotiated. You cannot change the duplex mode of autonegotiation ports.

To set the duplex mode of a port, perform this task in privileged mode:

Task Command

Step 1 Set the duplex mode of a port.

set port duplex mod num/port num {full | half}

Step 2 Verify that the duplex mode of the port is configured correctly.

show port [mod_num[/port_num]]

Task	Command
Step 1 Set the duplex mode of a port.	set port duplex mod num/port num {full \| half}
Step 2 Verify that the duplex mode of the port is configured correctly.	show port [mod_num[/port_num]]

This example shows how to set the duplex mode to half duplex on port 2/1:

Console> (enable) set port duplex 2/1 half

Port 2/1 set to half-duplex.
Console> (enable)

Checking Connectivity

Use the ping and traceroute commands to test connectivity out Ethernet, Fast Ethernet, or Gigabit Ethernet ports.

To check connectivity out a port, perform this task in privileged mode:

Task Command

Step 1 Ping a remote host that is located out the port you want to test.

ping [-s] host [packet_size] [packet_count]

Step 2 Trace the hop-by-hop route of packets from the switch to a remote host located out the port you want to test.

traceroute host

Step 3 If the host is unresponsive, check the IP address and default gateway configured on the switch.

show interface
show ip route

Task	Command
Step 1 Ping a remote host that is located out the port you want to test.	ping [-s] host [packet_size] [packet_count]
Step 2 Trace the hop-by-hop route of packets from the switch to a remote host located out the port you want to test.	traceroute host
Step 3 If the host is unresponsive, check the IP address and default gateway configured on the switch.	show interface show ip route

This example shows how to ping a remote host and how to trace the hop-by-hop path of packets through the network using traceroute:

Console> (enable) ping somehost

somehost is alive
Console> (enable) traceroute somehost

traceroute to somehost.company.com (10.1.2.3), 30 hops max, 40 byte packets
 1 engineering-1.company.com (173.31.192.206) 2 ms 1 ms 1 ms
 2 engineering-2.company.com (173.31.196.204) 2 ms 3 ms 2 ms
 3 gateway_a.company.com (173.16.1.201) 6 ms 3 ms 3 ms
 4 somehost.company.com (10.1.2.3) 3 ms * 2 ms
Console> (enable)

Using Gigabit Ethernet Modules

This section describes configuration information that is specific to the Catalyst 5000 series Gigabit Ethernet switching module (WS-X5403) and the Supervisor Engine III Gigabit uplink module (WS-U5534-GESX).

Note For information on configuring the nine-port Gigabit EtherChannel module (WS-X5410), refer to the Gigabit EtherChannel Module Installation and Configuration Note.

This section discusses the following topics:

Gigabit Ethernet Module Port Restrictions

Depending on the Catalyst 5000 series switch model, the supervisor engine model, and the slot placement of the Gigabit Ethernet module in the chassis, not all module ports may be active. Table 4-2 shows which ports on the three-port Gigabit Ethernet module (WS-X5403) are active when the module is installed in a Catalyst 5000 series switch.

Table 4-2: Three-Port Gigabit Ethernet Module (WS-X5403) Port Restrictions
Switch Gigabit Ethernet Switching Module Port Restrictions

Catalyst 5002

Port 1 active. Ports 2 and 3 are inactive.

Catalyst 5000

Port 1 active. Ports 2 and 3 are inactive.

Catalyst 5505

With Supervisor Engine III:
In slots 2 through 3---Port 1 on bus A, port 2 on bus B, and port 3 on bus C.
In slot 4---Port 1 on bus B, port 2 on bus A, and port 3 on bus C.
In slot 5---Port 1 on bus C, port 2 on bus B, and port 3 on bus A.

With Supervisor Engine II:
Any slot---Port 1 active. Ports 2 and 3 are inactive.

Catalyst 5509

With Supervisor Engine III:
Any slot---All ports active.

With Supervisor Engine II:
Any slot---Port 1 active. Ports 2 and 3 are inactive.

Catalyst 5500

With Supervisor Engine III:
In slots 2 through 5---Port 1 on bus A, port 2 on bus B, and port 3 on bus C.
In slots 6 through 8---Port 1 on bus B; ports 2 and 3 inactive.
In slots 9 through 12---Module cannot be inserted due to physical limitations.

With Supervisor Engine II:
In slots 2 through 8---Port 1 on bus B; ports 2 and 3 inactive.
In slots 9 through 12---Module cannot be inserted due to physical limitations.

Table 4-2: **Three-Port Gigabit Ethernet Module (WS-X5403) Port Restrictions**
Switch	Gigabit Ethernet Switching Module Port Restrictions
Catalyst 5002	Port 1 active. Ports 2 and 3 are inactive.
Catalyst 5000	Port 1 active. Ports 2 and 3 are inactive.
Catalyst 5505	With Supervisor Engine III: In slots 2 through 3---Port 1 on bus A, port 2 on bus B, and port 3 on bus C. In slot 4---Port 1 on bus B, port 2 on bus A, and port 3 on bus C. In slot 5---Port 1 on bus C, port 2 on bus B, and port 3 on bus A. With Supervisor Engine II: Any slot---Port 1 active. Ports 2 and 3 are inactive.
Catalyst 5509	With Supervisor Engine III: Any slot---All ports active. With Supervisor Engine II: Any slot---Port 1 active. Ports 2 and 3 are inactive.
Catalyst 5500	With Supervisor Engine III: In slots 2 through 5---Port 1 on bus A, port 2 on bus B, and port 3 on bus C. In slots 6 through 8---Port 1 on bus B; ports 2 and 3 inactive. In slots 9 through 12---Module cannot be inserted due to physical limitations. With Supervisor Engine II: In slots 2 through 8---Port 1 on bus B; ports 2 and 3 inactive. In slots 9 through 12---Module cannot be inserted due to physical limitations.

Configuring Flow Control on Gigabit Ethernet Module

The Gigabit Ethernet switching module (WS-X5403) and the Gigabit uplink module (WS-U5534-GESX) use flow control to inhibit the transmission of packets to the module for a period of time. Typically, if the receive buffer becomes full, the module transmits a "pause" packet that tells remote devices to delay sending more packets for a specified period of time. In addition, the Gigabit Ethernet module can receive and act upon "pause" packets from other devices.

Use the set port flow control command to configure flow control on the Gigabit Ethernet module and uplinks. Table 4-3 lists the set port flowcontrol command keywords and describes their functions.

Table 4-3: Gigabit Ethernet Flow Control Keyword Functions
Keywords Function

receive on

The port uses flow control dictated by the neighbor port.

receive desired

The port uses flow control if the neighbor port uses it, and does not use flow control if the neighbor port does not use it.

receive off

The port does not use flow control, regardless of whether flow control is requested by the neighbor port.

send on

The port sends flow-control frames to the neighbor port.

send desired

The port sends flow-control frames to the neighbor port if the neighbor port asks to use flow control.

send off

The port does not send flow-control frames to the neighbor port.

**Table 4-3: Gigabit Ethernet Flow Control Keyword Functions**
Keywords	Function
receive on	The port uses flow control dictated by the neighbor port.
receive desired	The port uses flow control if the neighbor port uses it, and does not use flow control if the neighbor port does not use it.
receive off	The port does not use flow control, regardless of whether flow control is requested by the neighbor port.
send on	The port sends flow-control frames to the neighbor port.
send desired	The port sends flow-control frames to the neighbor port if the neighbor port asks to use flow control.
send off	The port does not send flow-control frames to the neighbor port.

To configure flow control on a Gigabit Ethernet port, perform this task in privileged mode:

Task Command

Step 1 Set the flow-control parameters on a Gigabit Ethernet port.

set port flowcontrol {receive | send} mod_num/port_num {off | on | desired}

Step 2 Verify the flow-control configuration.

show port flowcontrol

Task	Command
Step 1 Set the flow-control parameters on a Gigabit Ethernet port.	set port flowcontrol {receive \| send} mod_num/port_num {off \| on \| desired}
Step 2 Verify the flow-control configuration.	show port flowcontrol

This example shows how to turn transmit and receive flow control on and how to verify the flow-control configuration:

Console> (enable) set port flowcontrol send 3/1 on

Port 3/1 will send flowcontrol to far end.
Console> (enable) set port flowcontrol receive 3/1 on

Port 3/1 will require far end to send flow control
Console> (enable) show port flowcontrol

Port    Send-Flowcontrol    Receive-Flowcntl    RxPause    TxPause
            Admin      Oper            Admin      Oper
----- ----------------    ----------------    -------    -------
  3/1    on            disagree    on            disagree    0                0
  3/2    off          off              off          off              0                0
  3/3    desired  on                desired  off              10              10
Console> (enable)

Configuring Fast EtherChannel

These sections describe how to configure Fast EtherChannel on Catalyst 5000 series Fast Ethernet ports:

Understanding How Fast EtherChannel Works

Fast EtherChannel provides parallel bandwidth of up to 800 Mbps (full duplex) between a Catalyst 5000 series switch and another switch or host by grouping multiple Fast Ethernet interfaces into a single logical transmission path.

Fast EtherChannel segments must be contiguous ports on a Fast EtherChannel-capable Fast Ethernet switching module. You can configure Fast Ethernet ports into Fast EtherChannel groups containing two or four segments, yielding 400- or 800-Mbps bidirectional bandwidth, respectively.

Inbound broadcast and multicast packets on one segment in a channel are blocked from returning on any other segment of the channel. Outbound broadcast and multicast packets are sent through only one channel segment.

If a segment within a channel fails, traffic previously carried over the failed link switches to the remaining segments within the channel. A trap is sent upon a failure identifying the switch, the channel, and the failed link.

Channels are configured using the standard CLI or Simple Network Management Protocol (SNMP).

The Port Aggregation Protocol (PAgP) facilitates the automatic creation of Fast EtherChannel links by exchanging packets between Fast EtherChannel-capable ports. The protocol learns the capabilities of port groups dynamically and informs the neighboring ports. Once PAgP identifies correctly paired Fast EtherChannel links, it groups the ports into a channel. The channel is then added to the spanning tree as a single bridge port.

PAgP includes four user-configurable channel modes: on, off, auto, and desirable. Each mode affects the way a port handles PAgP packets. By default, ports are in auto mode. Table 4-4 describes each mode.

Table 4-4: Channel Modes
Mode Description

on

Forces the port to channel without negotiation.

off

Prevents the port from channeling.

auto

Places a port into a passive negotiating state, in which the port responds to PAgP packets it receives but does not initiate PAgP packet negotiation. (Default)

desirable

Places a port into an active negotiating state, in which the port initiates negotiations with other ports by sending PAgP packets.

**Table 4-4: Channel Modes**
Mode	Description
on	Forces the port to channel without negotiation.
off	Prevents the port from channeling.
auto	Places a port into a passive negotiating state, in which the port responds to PAgP packets it receives but does not initiate PAgP packet negotiation. (Default)
desirable	Places a port into an active negotiating state, in which the port initiates negotiations with other ports by sending PAgP packets.

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 port speed, trunking state, VLAN numbers, and so on.

Channel ports can be in different channel modes as long as the modes are compatible. For instance, a port in desirable mode can form a channel successfully with another port that is in desirable or auto mode. Similarly, a port in auto mode can form a channel with another port in desirable mode. However, a port in auto mode cannot form a channel with another port that is also in auto mode, since neither port will initiate negotiation.

Hardware Support for Fast EtherChannel

The two-port supervisor engine modules that support Fast EtherChannel (model numbers WS-X5505, WS-X5506, WS-X5509, and WS-X5530) on Catalyst 5000 series switches support a single configuration: one channel of two ports.

The following switching modules support Fast EtherChannel in a number of configurations:

10/100BaseTX Fast EtherChannel switching module, 12-port (WS-X5203)
10/100BaseTX Fast Ethernet switching module, 24-port (WS-X5225)
100BaseFX Fast EtherChannel switching module, 12-port (WS-X5201)
100BaseFX Fast EtherChannel backbone switching module, 12-port (WS-X5201R)

On the 12-port modules, the ports form three groups of four ports each (ports 1-4, 5-8, and 9-12). On the 24-port module, the ports form three groups of eight ports each (ports 1-8, 9-16, and 17-24). A Fast EtherChannel must be composed of contiguous ports from the same group. A channel cannot have some ports from one group and some ports from another. Each group of four ports can be channeled in any the following ways:

One channel of four contiguous ports (for example, ports 1-4 channeled or ports 9-12 channeled)
Two channels with two contiguous ports in each channel (for example, ports 1-2 channeled and ports 3-4 channeled)
One channel of the first two contiguous ports in the group with the other two ports in the group not channeled (for example, ports 5-6 channeled and ports 7-8 not channeled)
One channel of any two contiguous ports in the group with the other ports in the group not channeled (for example, ports 1-2 channeled and ports 3-4 not channeled, ports 2-3 channeled and ports 1 and 4 not channeled, or ports 3-4 channeled and ports 1-2 not channeled). This configuration applies to the WS-X5201, WS-X5203, and WS-X5224 modules only.
No ports channeled
On the 10/100BaseTX Fast Ethernet switching module, 24-port (WS-X5225), ports 3-4 can form a channel without ports 1-2 also forming a channel

Fast EtherChannel Configuration Guidelines

If improperly configured, some Fast EtherChannel ports are disabled automatically to avoid network loops and other problems. Use the following guidelines to avoid configuration problems:

Assign all ports in a channel to the same VLAN(s), or configure them as trunk ports.
If you configure the channel as a trunk, configure the same trunk mode on all the ports in the channel, on both ends of the link. Configuring ports in a channel in different trunk modes can have unexpected results.
Set the same allowed range of VLANs on all the ports in a trunking channel. When the allowed range of VLANs is not the same for all ports in a channel, VLANs are added selectively to some ports and not to the rest. The ports to which the VLAN is not added will drop the packets of that VLAN. If the allowed range of VLANs is not the same for a port list, the ports do not form a channel even when set to the auto or desirable mode with the set port channel command.
Do not configure the ports in a channel as dynamic VLAN ports. Doing so can adversely affect switch performance.
Configure all ports in a channel to operate at the same speed and duplex mode (full or half duplex).
If you configure a broadcast limit on the ports, configure the broadcast limit as a percentage limit for the channeled ports. With a packets-per-second broadcast limit, unicast packets might get dropped for one second when the broadcast limit is exceeded.
Disable the port security feature on the channeled ports. If you enable port security for a channeled port, the port shuts down when it receives packets with source addresses that do not match the secure address of the port.
Enable all ports in a channel. If you disable a port in a channel, it is treated as a link failure and its traffic is transferred to one of the remaining ports in the channel.
Ensure that all ports in a channel have the same configuration on both ends of the channel.
Note that port aggregation is constrained by the Ethernet bundling hardware so that the system prevents certain ports or groups of ports from forming channels.

Configuring Fast EtherChannel

To configure Fast EtherChannel on a group of Fast Ethernet ports, perform this task in privileged mode:

Task Command

Step 1 Make sure that the ports you want to channel are configured correctly. (Refer to the "Fast EtherChannel Configuration Guidelines" section earlier in this chapter.)

Step 2 Create the Fast EtherChannel on the desired ports.

set port channel port_list {on | off | auto | desirable}

Step 3 Verify the Fast EtherChannel configuration.

show port channel [mod_num[/port_num]] [info | statistics]

Task	Command
Step 1 Make sure that the ports you want to channel are configured correctly. (Refer to the "Fast EtherChannel Configuration Guidelines" section earlier in this chapter.)
Step 2 Create the Fast EtherChannel on the desired ports.	set port channel port_list {on \| off \| auto \| desirable}
Step 3 Verify the Fast EtherChannel configuration.	show port channel [mod_num[/port_num]] [info \| statistics]

This example shows how to create a two-port channel and verify the configuration:

Console> (enable) set port channel 1/1-2 on

Port(s) 1/1-2 channel mode set to on.
Console> (enable) 06/30/1998,17:09:32:PAGP-5:Port 1/1 left bridge port 1/1.
06/30/1998,17:09:32:PAGP-5:Port 1/2 left bridge port 1/2.
06/30/1998,17:09:33:PAGP-5:Port 1/1 joined bridge port 1/1-2.
06/30/1998,17:09:33:PAGP-5:Port 1/2 joined bridge port 1/1-2.
Console> (enable) show port channel

Port  Status     Channel   Channel     Neighbor                  Neighbor
                 mode      status      device                    port
----- ---------- --------- ----------- ------------------------- ---------- 
 1/1  connected  on        channel     WS-C2926    007475320     1/1       
 1/2  connected  on        channel     WS-C2926    007475320     1/2       
----- ---------- --------- ----------- ------------------------- ---------- 
Console> (enable)

To remove an Ethernet channel, perform this task in privileged mode:

Task Command

Step 1 Remove an Ethernet channel.

set port channel port_list off

Step 2 Verify the Fast EtherChannel configuration.

show port channel [mod_num[/port_num]] [info | statistics]

Task	Command
Step 1 Remove an Ethernet channel.	set port channel port_list off
Step 2 Verify the Fast EtherChannel configuration.	show port channel [mod_num[/port_num]] [info \| statistics]

This example shows how to disable a channel and how to verify the configuration:

Console> (enable) set port channel 1/1-2 off

Port(s) 1/1-2 channel mode set to off.
Console> (enable) show port channel

No ports channelling
Console> (enable)

Using Protocol Filtering

These sections describe how to configure protocol filtering on Catalyst 5000 series Ethernet VLANs and on Ethernet, Fast Ethernet, and Gigabit Ethernet ports:

Understanding How Protocol Filtering Works

A Supervisor Engine III that has a NetFlow Feature Card (NFFC) can support protocol filtering within a port VLAN.

Protocol filtering is supported only on Ethernet VLANs and on nontrunking Ethernet, Fast Ethernet, and Gigabit Ethernet ports. Trunking ports are always members of all the protocol groups. Protocol filtering is disabled by default on all Ethernet VLANs. In addition to configuring a VLAN to the port, you can configure the port to be a member of one or more of the protocol groups. Filtering is not done on trunk ports; therefore, there are no interoperability issues with switches without the NFFC card. Layer 2 protocols, such as Spanning-Tree Protocol and Cisco Discovery Protocol, are not affected by protocol filtering.

If the NFFC is installed, the supervisor engine software supports autolearning. With autolearning, ports become members of the protocol flood domain only after receiving packets of the corresponding protocol. For example, if a host supports both IP and Internetwork Packet Exchange (IPX) and the host is using only IP, the port to which this host is connected is configured as auto for IPX. This port does not receive any IPX flood traffic. When the host actually sends an IPX packet, it is detected by the supervisor, and the port is added to the IPX group, which allows the port to start receiving the IPX flood traffic.

Dynamic ports and ports that have port security enabled are members of all protocol groups.

You can configure a port with the following options: on, off, and auto for a particular protocol. If the configuration is set to on, it receives all the flood traffic for that protocol; if it is set to off, it does not receive any flood traffic for that protocol; and if the port configuration is set to auto, it is added to the group only after receiving packets of the specific protocol. Initially, the port does not receive any flood packets for that protocol. When the corresponding protocol packets are received on that port, the supervisor module detects this condition and adds the port to the protocol group.

By default, ports are configured to on for the IP protocol groups. You can configure the ports to auto for IP if only clients are connected to the ports. The default port configuration for IPX and Group is auto. Autoconfigured ports are removed from the protocol group if no packets are received for that protocol within 60 minutes. Ports are also removed from the protocol group when the supervisor detects a link down.

An NFFC provides broadcast and unicast flood traffic filtering based on the port's membership to different protocol groups in addition to the port VLAN. The NFFC does not process Token Ring packets.

With protocol filtering enabled, ports are grouped on a protocol basis. The NFFC classifies packets into the following four protocol groups:

IP
IPX
Appletalk, Decnet, and Vines
Packets not belonging to any of these protocols

A port can be a member of one or more of the first three groups.

Configuring Protocol Filtering

To configure protocol filtering on Ethernet, Fast Ethernet, or Gigabit Ethernet ports, perform this task in privileged mode:

Task Command

Step 1 Enable protocol filtering on the switch.

set protocolfilter {enable | disable}

Step 2 Set the protocol membership of the desired ports.

set port protocol mod_num/port_num {ip | ipx | group} {on | off | auto}

Step 3 Verify the port filtering configuration.

show port protocol [mod_num[/port_num]]

Task	Command
Step 1 Enable protocol filtering on the switch.	set protocolfilter {enable \| disable}
Step 2 Set the protocol membership of the desired ports.	set port protocol mod_num/port_num {ip \| ipx \| group} {on \| off \| auto}
Step 3 Verify the port filtering configuration.	show port protocol [mod_num[/port_num]]

This example shows how to enable protocol filtering, set the protocol membership of ports, and verify the configuration:

Console> (enable) set protocolfilter enable

Protocol filtering enabled on this switch.
Console> (enable) set port protocol 2/1 ip off

IP protocol disabled on port 2/1.
Console> (enable) set port protocol 5/1 ip auto

IP protocol set to auto mode on module 5/1.
Console> (enable) show port protocol 1/1-2

Port	 Vlan	      IP	    IP Hosts  	IPX	      IPX Hosts	   Group   Group Hosts
-----	----------	------	----------	---------	------------	--------	----------------
1/1	  1         	on	       10	    auto-on   	4           	auto-off	 0
1/2  trunking	  on        	-    	on        	-	           on	       -
Console> (enable)

Ethernet Switching Configuration Examples

Figure 4-1 shows an example Ethernet configuration for a single Catalyst 5000 series switch. This example shows all devices on each module as either full duplex or half duplex. However, you can configure each port on each module independently for either full- or half-duplex operation. In addition, this example shows a direct correlation between port speed and traffic priority, although the two parameters are completely independent.

Note A Catalyst 5000 switch is used in this example, but the configuration can apply to all Catalyst 5000 series switches.

Figure 4-1: Single Catalyst 5000 Series Switch Configuration

The example configuration shown in Figure 4-1 is based on the following assumptions:

The following elements are in place:
- 1 full-duplex, Fast Ethernet connection to a router
- 13 full-duplex, Fast Ethernet connections to servers (1 connection on the supervisor engine module and 12 connections on the 10/100BaseTX module in slot 2)
- 12 half-duplex, 10BaseFL Ethernet connections to hubs
- 12 full-duplex, 100BaseFX Fast Ethernet connections to other switches
- 24 half-duplex, 10BaseT Ethernet connections to network devices
- Low traffic priority assignments for all 10BaseT and 10BaseFL connections
- High traffic priority assignments for all Fast Ethernet connections
Because all ports in VLAN 1 are set to the default value, no customizing is necessary for the ports.
For port 2, 10/100BaseTX defaults to auto, which automatically sets the duplex.

This example shows how to configure Ethernet on a Catalyst 5000 series switch:

Step 1 Configure a name for the port by entering the set port name command. You see this display:

Console> (enable) set port name 1/1 Router Connection

Port 1/1 name set.

Console> (enable) set port name 1/2 Server 1

Port 1/2 name set.

Console> (enable) set port name 2/1 Server 2

Port 2/1 name set.

Console> (enable) set port name 2/2 Server 3

Port 2/2 name set.

.

Console> (enable) set port name 2/12 Server 13

Port 2/12 name set.

Console> (enable) set port name 3/1 Hub 1

Port 3/1 name set.

Console> (enable) set port name 3/1 Hub 2

Port 3/2 name set.

Console> (enable) set port name 3/1 Hub 3

Port 3/3 name set.

.

Console> (enable) set port name 3/12 Nodename 12

Port 3/12 name set.

Console> (enable) set port name 4/1 Switch 1

Port 4/1 name set.

Console> (enable) set port name 4/2 Switch 2

Port 4/2 name set.

Console> (enable) set port name 4/3 Switch 3

Port 4/3 name set.

.

Console> (enable) set port name 4/24 Switch 12

Port 4/24 name set.

Console> (enable) set port name 5/1 Switch 13

Port 5/1 name set.

Console> (enable) set port name 5/2 Switch 14

Port 5/2 name set.

Console> (enable) set port name 5/3 Switch 15

Port 5/3 name set.

.

Console> (enable) set port name 5/24 Nodename 36

Port 5/24 name set

Step 2 Configure the priority level for the port by entering the set port level command. You see this display:

Console> (enable) set port level 1/1 high

Port 1/1 level set to high.

Console> (enable) set port level 1/2 high

Port 1/2 level set to high.

Console> (enable) set port level 2/1 high

Port 2/1 level set to high.

Console> (enable) set port level 2/2 high

Port 2/2 level set to high.

Console> (enable) set port level 2/3 high

Port 2/3 level set to high.

.

Console> (enable) set port level 2/12 high

Port 2/12 level set to high.

Console> (enable) set port level 3/1 normal

Port 3/1 level set to normal.

Console> (enable) set port level 3/2 normal

Port 3/2 level set to normal.

Console> (enable) set port level 3/3 normal

Port 3/3 level set to normal.

.

Console> (enable) set port level 3/12 normal

Port 3/12 level set to normal.

Console> (enable) set port level 4/1 normal

Port 4/1 level set to normal.

Console> (enable) set port level 4/2 normal

Port 4/2 level set to normal.

Console> (enable) set port level 4/3 normal

Port 4/3 level set to normal.

.

Console> (enable) set port level 4/24 normal

Port 4/24 level set to normal.

Console> (enable) set port level 5/1 normal

Port 5/1 level set to normal.

Console> (enable) set port level 5/2 normal

Port 5/2 level set to normal.

Console> (enable) set port level 5/3 normal

Port 5/3 level set to normal.

.

Console> (enable) set port level 5/24 normal

Port 5/24 level set to normal.

Step 3 Configure a name for the port by entering the set port speed command. You see this display:

Console> (enable) set port speed 2/1 100

Port 2/1 speed set to 100 Mbps.

Console> (enable) set port speed 2/2 100

Port 2/2 speed set to 100 Mbps.

Console> (enable) set port speed 2/3 100

Port 2/3 speed set to 100 Mbps.

Console> (enable) set port speed 2/4 100

Port 2/4 speed set to 100 Mbps.

Console> (enable) set port speed 2/5 100

Port 2/5 speed set to 100 Mbps.

.

Console> (enable) set port speed 2/12 100

Port 2/12 speed set to 100 Mbps.

Step 4 Configure the transmission type of the port (half or full duplex) by entering the set port duplex command. You see this display:

Console> (enable) set port duplex 1/1 full

Port 1/1 set to full-duplex.

Console> (enable) set port duplex 1/2 full

Port 1/2 set to full-duplex.

Console> (enable) set port duplex 2/1 full

Port 2/1 set to full-duplex.

Console> (enable) set port duplex 2/2 full

Port 2/2 set to full-duplex.

Console> (enable) set port duplex 2/3 full

Port 2/3 set to full-duplex.

.

Console> (enable) set port duplex 2/12 full

Port 2/12 set to full-duplex.

Port 3/1 set to half-duplex.

Console> (enable) set port duplex 3/2 half

Port 3/2 set to half-duplex.

Console> (enable) set port duplex 3/3 half

Port 3/3 set to half-duplex.

.

Console> (enable) set port duplex 3/12 half

Port 3/12 set to half-duplex.

Console> (enable) set port duplex 4/1 full

Port 4/1 set to half-duplex.

Console> (enable) set port duplex 4/2 full

Port 4/2 set to half-duplex.

Console> (enable) set port duplex 4/3 full

Port 4/3 set to half-duplex.

.

Console> (enable) set port duplex 4/24 full

Port 4/24 set to half-duplex.

Console> (enable) set port duplex 5/1 half

Port 5/1 set to half-duplex.

Console> (enable) set port duplex 5/2 half

Port 5/2 set to half-duplex.

Console> (enable) set port duplex 5/3 half

Port 5/3 set to half-duplex.

.

Console> (enable) set port duplex 5/24 half

Port 5/24 set to half-duplex.

Step 5 To verify the Ethernet configuration, enter the show port command. After entering this command, you see a display similar to the verification example in the section "Setting the Port Name."

Table of Contents

Configuring Ethernet, Fast Ethernet, and Gigabit Ethernet Switching