This document explains the concept of redundant interface on firewall. We will discuss the whole concpet and configuration sample for the same.
There are no specific requirements for this document.
ASA 5500 series running 7.X and above
A logical redundant interface is a pair of an active and a standby physical interface. When the active interface fails, the standby interface becomes active. From firewall perspective this event is completely transparent and can be viewed as a single logical interface. We can use redundant interfaces to increase the security appliance reliability. This feature is separate from device-level failover, but you can configure redundant interfaces as well as failover if desired. We can configure upto 8 redundant interfaces.
Redundant interface are number from 1 to 8 and have the name redundant X. When adding physical interfaces to the redundant pair, please make sure there is no configuration on it and interface is also in no shutdown state. This is just a precaution, the firewall will remove these settings when adding the physical interface to a new group. The logical redundant interface will take the MAC address of the first interface added to the group. This MAC address is not changed with the member interface failures, but changes when you swap the order of the physical interfaces to the pair.
Once we have configured a redundant interface, we can assign it a name and a security level, followed by an IP address. The procedure is the same as with any interface in the system.
no ip address
no ip address
ip address 220.127.116.11 255.255.255.0
You can use the following command to verify--
ciscoasa(config)# show interface redundant 1
Interface Redundant1 "outside", is up, line protocol is up
Hardware is i82546GB rev03, BW 1000 Mbps, DLY 10 usec