Chapter 37 Configuring EtherChannels and Link-State Tracking

Displaying EtherChannel, PAgP, and LACP Status

Displaying EtherChannel, PAgP, and LACP Status

To display EtherChannel, PAgP, and LACP status information, use the privileged EXEC commands described in Table 37-4:

Table 37-4 Commands for Displaying EtherChannel, PAgP, and LACP Status

Command

Description

 

 

show etherchannel [channel-group-number{detail

Displays EtherChannel information in a brief, detailed, and

port port-channel protocol summary}] {detail

one-line summary form. Also displays the load-balance or

load-balance port port-channel protocol

frame-distribution scheme, port, port-channel, and protocol

summary}

information.

 

 

show pagp [channel-group-number] {counters

Displays PAgP information such as traffic information, the

internal neighbor}

internal PAgP configuration, and neighbor information.

 

 

show lacp [channel-group-number] {counters

Displays LACP information such as traffic information, the

internal neighbor}

internal LACP configuration, and neighbor information.

 

 

You can clear PAgP channel-group information and traffic counters by using the clear pagp {channel-group-numbercounters counters} privileged EXEC command.

You can clear LACP channel-group information and traffic counters by using the clear lacp {channel-group-numbercounters counters} privileged EXEC command.

For detailed information about the fields in the displays, see the command reference for this release.

Understanding Link-State Tracking

Link-state tracking, also known as trunk failover, is a feature that binds the link state of multiple interfaces. For example, link-state tracking provides redundancy in the network when used with server NIC adapter teaming. When the server network adapters are configured in a primary or secondary relationship known as teaming, if the link is lost on the primary interface, connectivity is transparently switched to the secondary interface.

As shown in Figure 37-6, server 1 and server 2 use switch A for primary links and switch B for secondary links to switches and other network devices. Server 3 and server 4 use switch B for primary links and switch A for secondary links. This configuration ensures that the traffic flow is balanced in the network. Ports connected to servers are referred to as downstream ports, and ports connected to distribution switches and network devices are referred to as upstream ports.

Switch A provides primary links to server 1 and server 2 through link-state group 1. Port 1 is connected to server 1, and port 2 is connected to server 2. Port 3 and port 4 on switch A also provide secondary links through link-state group 2. Port 5 and port 6 are connected to distribution switch 1 through link-state group 1, and port 7 and port 8 are also connected to distribution switch 2 through link-state group 2.

Switch B provides primary links to server 3 and sever 4 through link-state group 2 and secondary links to server 1 and server 2 through link-state group 1. Port 3 and port 4 are connected to server 3 and server 4 through the primary links in link-state group 1. Port 1 and port 2 are connected to server 1 and server 2 through secondary links in link-state group 2. Port 5 and port 6 are connected to distribution switch 2 through link-state group 2; port 7 and port 8 are connected to distribution switch 1 through link-state group 1.

 

 

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

 

 

 

 

 

 

OL-9775-02

 

 

37-23

 

 

 

 

 

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Cisco Systems 3750E manual Displaying EtherChannel, PAgP, and Lacp Status, Understanding Link-State Tracking, 37-23