For the past couple of weeks i have been trying to figure out how to make firewall cluster, each having different ISP.
I have found few guides on how to do it with one ISP using technologies like keepalived and conntrackd. For example this one.
Is there a way to use keepalived for ISP failover? For example if ISP1 goes down the backup firewall takes over with ISP2? And if not what are the other options?
If there are any questions I'm happy to answer.