The article includes step-by-step instructions on how to setup automatic failover and connection state synchronization. Linux Journal makes the issues available online after two months so if you can't wait that long you can buy it online or at your favorite newsstand.
Wednesday, April 13, 2011
Linux Journal - Configuring Linux HA firewall pairs
The May 2011 issue of the Linux Journal magazine, which is now available in print edition, includes an article I wrote about how to use Firewall Builder to configure a High Availability pair of Linux iptables firewalls.