Connectivity Guide

Event VLT action on primary node VLT action on secondary node UFD action
Reboot of VLT secondary peer No action After reboot, runs the delay
restore timer. Both the upstream
and downstream VLT port-
channel remains disabled until
the timer expires.
UFD error-disables the
downstream VLT port-channel
as the upstream VLT port-
channel is operationally down.
After the timer expires, UFD
receives operationally up of
upstream VLT port-channel and
sends clear error-
disable of downstream VLT
port-channel to IFM.
Reboot of VLT primary peer Primary becomes secondary
peer and runs delay restore timer
Secondary becomes primary UFD error-disables the
downstream VLT port-channel
as the upstream VLT port-
channel is operationally down.
After the timer expires, UFD
receives operationally up of
upstream VLT port-channel and
sends clear error-
disable of downstream VLT
port-channel to IFM.
Discovery interface added to
UFD group
Invalid conguration Invalid conguration Invalid conguration
UFD group member congured
as discovery interface
Invalid conguration Invalid conguration Invalid conguration
UFD group member made as
VLT port-channel
No action No action UFD uses fabric status to track
the UFD group status.
VLT port-channel added as
member of UFD group
No action No action UFD uses fabric status to track
the UFD group status.
VLT port-channel conguration
removed from the port-channel
interface which is upstream
member of UFD group
No action No action Stops tracking the fabric status
for the UFD group. Starts
tracking the local port-channel
operational status, which is
upstream member of the UFD
group.
Fabric Status is operationally up No action No action Enables the downstream
members, that is clears the
error-disabled state.
Fabric Status is operationally
down
No action No action Disables the downstream
members, that is sets the error-
disabled state.
Sample congurations of UFD on VLT
The following examples show some of the uplink-state groups on VLT.
In the following illustration, both the upstream and downstream members are part of VLT port-channels. The uplink-state group includes
both the VLT port-channels as members.
862
Uplink Failure Detection