My network is below, it's currently just an ordinary 192.168.0.0/24, the branch offices needs to have access to resources on the main site. Currently all internet traffic go across the bridge and through the Watchguards WAN connection. The Watchguard issues all DHCP leases to both sites.
Currently the Branch site WAN connection isn't operational but when it is, I want to make it so if the wireless bridge fails all traffic to the Main Site is routed over a VPN over the internet automatically.
How can I achieve this using the products and their features at hand? I'm not very familiar with the products. I understand that the Watchguard has a BOVPN feature and the SSG20 has VPN support but how would I also setup the routing? Is it possible to convert the wireless bridge into a WAN and just try to setup a Multi-WAN setup (with one WAN being a VPN) on both products?