Cisco CATALYST 2960

38-24
Catalyst 2960 and 2960-S Switches Software Configuration Guide, Release 15.0(1)SE
OL-26520-01
Chapter 38 Configuring EtherChannels and Link-State Tracking
Configuring Link-State Tracking
Link-State Tracking Configuration Guidelines
Follow these guidelines to avoid configuration problems:
• An interface that is defined as an upstream interface cannot also be defined as a downstream
interface in the same or a different link-state group. The reverse is also true.
• Do not enable link-state tracking on individual interfaces that will be part of a downstream
Etherchannel interface.
• An interface cannot be a member of more than one link-state group.
• You can configure only two link-state groups per switch.
Configuring Link-State Tracking
Beginning in privileged EXEC mode, follow these steps to configure a link-state group and to assign an
interface to a group:
This example shows how to create a link-state group and configure the interfaces:
Switch# configure terminal
Switch(config)# link state track 1
Switch(config)# interface range gigabitethernet1/0/21 -22
Switch(config-if)# link state group 1 upstream
Switch(config-if)# interface gigabitethernet1/0/1
Switch(config-if)# link state group 1 downstream
Switch(config-if)# interface gigabitethernet1/0/3
Switch(config-if)# link state group 1 downstream
Switch(config-if)# interface gigabitethernet1/0/5
Switch(config-if)# link state group 1 downstream
Switch(config-if)# end
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
link state track number Create a link-state group, and enable link-state tracking. The
group number can be 1 to 2; the default is 1.
Step 3
interface interface-id Specify a physical interface or range of interfaces to configure,
and enter interface configuration mode.
Valid interfaces include switch ports in access or trunk mode
(IEEE 802.1q), routed ports, or multiple ports bundled into an
upstream EtherChannel interface (static, PAgP, or LACP), also in
trunk mode.
Note Do not enable link-state tracking on individual interfaces
that will be part of a downstream Etherchannel interface.
Step 4
link state group [number] {upstream |
downstream}
Specify a link-state group, and configure the interface as either
an upstream or downstream interface in the group.The group
number can be 1 to 2; the default is 1.
Step 5
end Return to privileged EXEC mode.
Step 6
show running-config Verify your entries.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration file.