ASA Redundant/Dual Connections to the SAME ISP

[Scott Pickles]

Is it possible to connect two ports on an ASA to the same ISP for physical port redundancy?  I know it's possible to connect to two different ISPs with different subnets, but in this case it would be the same ISP, same subnet.  I'm expecting the answer to be 'no' and that I'd have to bring up a 'cold spare' interface should the primary interface go down.  The ASA model is either 5520 or 5512-X, and I'd have to go get the software versions if anyone would like that information.

[Jon Marshall · Accepted solution]

You can't give two ports an IP from the same subnet in the same context no.

But you could either -

1) use etherchannel

or

2) use the redundant interface feature where you use two ports but only one is active and if it fails the other takes over with the same IP address

Jon

[Scott Pickles]

Thanks Jon.  I'll opt for the redundant interface option since I'm modifying an HSRP installation to have links to the firewall (currently there is only one link from one of the core switches).