Displaying Information About Etherchannels - Cisco Catalyst 2000 Configuration Handbook

68 Cisco LAN Switching Configuration Handbook
A second EtherChannel is configured to use LACP. The LACP system priority is set to
8192 so that this switch will become the higher-priority decision maker. Ports 6/1, 6/2,
6/7, and 6/8 all belong to LACP administrative key 101, forming a common aggregate
link. Ports 6/1 and 6/2 are given a port priority of 100, which is less than the default 128.
These ports are used in the LACP bundle first. If for some reason ports 6/7 or 6/8 cannot
be used in the EtherChannel, they are placed in a "standby" state and used if another port
fails. Each of the bundled ports is put into the active LACP mode and is willing to initiate
an EtherChannel with the far-end switch:
(global) interface fastethernet 4/1
(interface) channel-group 100 mode desirable non-silent
(global) interface fastethernet 4/2
(interface) channel-group 100 mode desirable non-silent
(global) interface fastethernet 5/1
(interface) channel-group 100 mode desirable non-silent
(global) interface fastethernet 5/2
(interface) channel-group 100 mode desirable non-silent
(global) port-channel load-balance src-dst-ip

Displaying Information About EtherChannels

Table 4-3 lists some switch commands that you can use to display helpful information
about EtherChannel links.
Tip If you are debugging an EtherChannel that will not form, remember that all ports
with the bundle must have the same attributes. For example, all the ports should have the
same allowed VLAN range, and so on.
The commands listed in Table 4-3 provide a great deal of information about EtherChannels
that are already formed. To be sure that the ports are all configured consistently, use other
show commands that display the port attributes. Beyond that, you sometimes have to
resort to looking through the switch configuration to spot port configurations that are not
identical or viewing the switch's log file.