A system and method of using a controller and firewall devices. Each of the firewall devices operate in an active mode during normal operation. The method may include the steps of determining when a first and/or second redundant data packet is received from a first/second firewall device, respectively, determining a valid sequence number, and transmitting the first/second redundant data packet to a target device when a sequence number of the first/second redundant data packet matches the valid sequence number and a first/second logical condition is satisfied, respectively. The first/second logical condition is at least one of the second/first firewall device is failed, a sequence number of the second/first redundant data packet varies from the valid sequence number, and the first/second firewall device is a primary firewall device.