37-24
Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter37 Configuring EtherChannels and Link-State Tracking
Configuring Link-State Tracking
In a link-state group, the upstream ports can become u navailable o r lose c onn ect ivity bec aus e t he
distribution switch or router fails, the cables are disconnected, or the link is lost. These are the
interactions between the downstream and upstream interfaces when link-state tracking is enabled:
•If any of the upstream interfaces are in the link-up state, th e downstream interfaces can change to or
remain in the link-up state.
•If all of the upstream interfaces become unavailable, link-state tracking automatically puts the
downstream interfaces in the error-disabled state. Connectivity to and from the servers is
automatically changed from the primary server interface to the secondary server interface.
As an example of a connectivity change from link-state group 1 to link-state group 2, when the
primary link from blade switch 1 to distribution switch 1 is lost, blade server 1 connects through its
secondary Ethernet server interface to blade switch 2 in link-state group 2.
•If the link-state group is configured, link-state tracking is disabled, and the upstr eam inter face s lose
connectivity, the link states of the downstream interfaces remain unchanged. Th e server does n ot
recognize that upstream connectivity has been lost and does not failover to the secondary interf a ce.
You can recover a downstream interface link-down condition by removing the failed downstream port
from the link-state group. To recover from multiple downstream interfaces, disable the link-state group.
Configuring Link-State Tracking
These sections describe how to configure link-state tracking ports:
•Default Link-State Tracking Configuration, page 37-24
•Link-State Tracking Configuration Guidelines, page 37-24
•Configuring Link-State Tracking, page37-25
•Displaying Link-State Tracking Status, page 37-26

Default Link-State Tracking Configuration

There are no link-state groups defined, and link-state trac king is n ot ena ble d f or any gro up.

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.
•An interface cannot be a member of more than one l ink-s tate group.
•You can configure only two link-state groups per nonstackable switch.
•You can configure only ten link-state groups perstackable switch.