I tweeted a little while ago about Nokia recently supporting interface failover within IPSO, well it looks like Cisco’s ASA Version 8 software can do it now too!
The following example creates two redundant interfaces:
asa(config)# interface redundant 1
asa(config-if)# member-interface gigabitethernet 0/0
asa(config-if)# member-interface gigabitethernet 0/1
asa(config-if)# interface redundant 2
asa(config-if)# member-interface gigabitethernet 0/2
asa(config-if)# member-interface gigabitethernet 0/3
Reference: Adding a Redundant Interface