In the event that the box looses power with the Failopen NIC, the Wan1 (eth1) & Lan (eth0) network segments become electrically common; In order for the wan router to pass traffic for the firewall, you will need to collect the MAC of the Wan 1 wan router & the Firewall's outside interface on the Lan -Once this has information been collected, youll need to change the MAC of the Wan1 interface to the MAC of the downstream outside interface of the firewall & youll need to change the MAC of the Lan interface to the MAC of the upstream Wan1 wan router; With this MAC spoofing in place, if the Fatpipe is on or off -Traffic will continue to flow using the correct MAC's