Configurable activation and deactivation delays provide a damping effect on the backup interface pair. This eliminates primary-to-backup switching in case of fluctuating underlying Layer 2 interfaces. You can configure the following backup delays with the backup delay command:
failure delay. The time in seconds between the primary interface going down and the backup interface activation. The default is 0 seconds. The maximum is 3600 seconds.
secondary disable delay. The time in seconds between the primary interface restoration and the backup interface deactivation. The default is 0 seconds. The maximum is 3600 seconds. Both interfaces are active during this time to enable a smooth transition for the routing protocols. To keep the backup interface active indefinitely, use never as the secondary disable delay.
You can use the following command to switch over immediately to the backup interface in case of failure, and pause 60 seconds before reverting to the primary interface:
Gxxx-001(super)# interface fastethernet 10/2
Gxxx-001(super-if:FastEthernet 10/2)# backup delay 0 60
Done!
Gxxx-001(super-if:FastEthernet 10/2)#
