As I tested the two-firewall CARP configuration I began to wonder. Every demonstration of CARP on pfSense I have ever read about or seen involves two firewalls: a primary firewall (the master) and the failover (the backup). Is it possible to have more than one system as a failover? Some of the documentation refers to a failover cluster, so at the very least, it seems to have been contemplated. But I could not find anything in the documentation on the official pfSense site or in the existing literature that describes how to do this.
Nevertheless, I was able to successfully implement, in a virtualized environment, a setup that incorporated three firewalls. I call this setup CARP with N firewalls, because, ...
