I'm building a failover firewall for a server cluster and started looking at the various options. I'm more familiar with carp on freebsd, but need to use linux for this project.

Searching google has produced several different projects, but no clear information about features they provide . CARP gave virtual interfaces that failover, I am not really clear on whether that's what corosync does, or is that what pacemaker does?

On the other hand I did get manage to get keepalived working. However, I noted that corosync provides native support for infiniband. This would be useful for me.

Perhaps someone could shed some light on the differences between:

1. corosync
2. keepalive
3. pacemaker
4. heartbeat

Which product would be the best fit for router failover?