Star topology with extra tunnel between two remote offices
I'm running pfSense 2 BETA 5 (Jan 17, 2011 build).
We have successfully created a star (hub and spoke?) OpenVPN VPN between the main office and several remote offices, where remote office computers can access each other indirectly, via the main office. For example, when a computer in remote office A pings a computer in remote office B, the packet first travels along the OpenVPN tunnel from remote office A to the main office and then travels along the OpenVPN tunnel from the main office to remote office B. We implemented this by getting the main office OpenVPN server to push the routes to the remote offices.
For performance purposes, it might be nice to add some direct tunnels between the busier remote offices. For example a tunnel from remote office A to remote office B. It would be nice if that direct tunnel could be used unless it is down, in which case the more roundabout route from A to head office to B could be used.
Would I use OSPF to accomplish this adaptive/dynamic routing goal? If so, does anyone have any pointers to get me started? I installed the OSPF package but I must admit that after staring at the config page for a few minutes, I'm not quite sure how to proceed.