Symptom
vPC secondary switch may flap vPC legs when Primary switch is reloaded.
This happens when Management interface is used for vPC peer keepalive msgs and vPc peer-link is on F3 cards or F2E cards starting 6.2(8) release
Conditions
vPC peer keepalive is configured to use Management interface and vPC peer-link is on F3 card or F2E starting 6.2(8).
Workaround
Use front panel port to run vPC peer keepalive to avoid this issue.
Further Problem Description
When vPC Primary switch is reloaded, F3 cards and F2E starting 6.2(8) brings down front panel ports 5 sec before Management port is brought down. Hence, on vPC secondary peer-link will go down first causing vPC legs to be suspended and after 5+ sec, Peer keepalive will go down. If "auto-recovery" is enabled, vPC secondary will bring up the legs when peer-keepalive goes down.
