Setting up redundant interfaces with an ASA 5510/5505

Redundant interfaces can provide you with some cover if one of the interfaces dies or the switch connected to it fails.

To setup a pair of redundent interfaces we should do the following:

interface e0/0
no nameif
no security-level
no ip address
exit

interface e0/1
no nameif
no security-level
no ip address
exit

interface redundant1
member-interface e0/0
member-interface e0/1
nameif red-inside
security-level 100
ip address 10.0.0.68 255.255.255.0

We can then check the configuration with:

show int

You should notice that both the line protocols of e0/0 and e0/1 are up, although one of the pair should be administratively down.