Routing over alternate network
First of all, I'm not sure if my title is correct. My situation is this: I have 3 locations, connecting through VPN to a central server (A). Unfortunately the central server is on a leg of internet that is not very stable. I have now created a direct wireless network to connect one location (B) to the central server (A). Location C however cannot connect directly over wireless, but the network between B and C is more stable than from (B || C) to A.
My goal now is to create a second VPN from C to B, and then route at all C traffic at B through the more stable Wireless link. Is this understandable? If not I'll try to do a drawing of it.
Can someone give me hints/ideas how to go about doing this?
PS. B to A and C to A are all ClarkConnect routers, while my VPN between A and B is on Soekris 4801 running pfSense. I want to use 2 Alix boards to do the additional VPN between C and B.