Bypassing A Vpc Consistency Check When A Peer Link Is Lost - Cisco Nexus 5000 Series Operation Manual

vPC Consistency Checks
S e n d d o c u m e n t a t i o n c o m m e n t s t o n 5 k d o c f e e d b a c k @ c i s c o . c o m

Bypassing a vPC Consistency Check When a Peer Link is Lost

The vPC consistency check message is sent by the vPC peer link. The vPC consistency check cannot be
performed when the peer link is lost. When the vPC peer link is lost, the operational secondary switch
suspends all of its vPC member ports while the vPC member ports remain on the operational primary
switch. If the vPC member ports on the primary switch flaps afterwards (for example, when the switch
or server that connects to the vPC primary switch is reloaded), the ports remain down due to the vPC
consistency check and you cannot add or bring up more vPCs.
Beginning with Cisco NX-OS Release 5.0(2)N2(1), the auto-recovery feature brings up the vPC links
when one peer is down. This feature performs two operations:
•
•
Note
The auto-recovery feature in Cisco NX-OS Release 5.0(2)N2(1) and later releases replaces the reload
restore feature in Cisco NX-OS Release 5.0(2)N1(1) and earlier releases.
The auto-recovery feature is disabled by default. To enable auto-recovery, enter the auto-recovery
command in the vPC domain mode.
This example shows how to enable the auto-recovery feature and to set the reload delay period:
switch(config)# vpc domain 10
switch(config-vpc-domain)# auto-recovery ?
<CR>
reload-delay
switch(config-vpc-domain)# auto-recovery reload-delay ?
<240-3600>
switch(config-vpc-domain)# auto-recovery reload-delay 240
Warning:
Cisco Nexus 5000 Series NX-OS Interfaces Operations Guide, Release 5.0(3)N2(1)
1-8
If both switches reload, and only one switch boots up, auto-recovery allows that switch to assume
the role of the primary switch. The vPC links come up after a configurable period of time if the vPC
peer-link and the peer-keepalive fail to become operational within that time. If the peer-link comes
up but the peer-keepalive does not come up, both peer switches keep the vPC links down. This
feature is similar to the reload restore feature in Cisco NX-OS Release 5.0(2)N1(1) and earlier
releases. The reload delay period can range from 240 to 3600 seconds.
When you disable vPCs on a secondary vPC switch because of a peer-link failure and then the
primary vPC switch fails, the secondary switch reenables the vPCs. In this scenario, the vPC waits
for three consecutive keepalive failures before recovering the vPC links.
Duration to wait after reload to recover vPCs
Time-out for restoring vPC links (in seconds)
Chapter 1 Virtual Port Channel Operations