Adding stateful failover to existing HA Pair

[Terence Lockette]

Hello all,

I have what I think is a fairly simple question.  Will adding stateful failover to an already existing failover HA pair on the ASA disrupt any services on the firewall?  I was looking at the failover pair and noticed that the 'failover link <NAME> <INTERFACE>' setting was missing and that the pair wasn't performing stateful failover.  I was trying to test in GNS3 but couldn't get the devices to detect each other.  I wasn't sure if it was a GNS3 issue or something else so I gave up as I ran out of time.  Anyway, I would like to get this added but would like to know if it's disruptive because if it is, I'll need to schedule a maintenance window.

Thanks.

[Ben Walters · Accepted solution]

We recently had a pair of 5525x that we needed to add stateful failover to for our phone system and we are able to enable it without a disruption in service. 

The phone system we have was also quite sensitive to disruptions too, if a failover occurred without stateful enabled all phones would reboot and join the backup controller. 

[Terence Lockette]

Thanks Ben.

I would suspect that of all traffic types, voice would be the most disruptive.  Seeing that you didn't experience any disruption when you enabled it makes me confident of the same as we also have voice traffic coming across our firewall as well.  I'll give it a shot and see what happens.