I've played around with a certificate based VPN (normally I don't do hardware) we've manged to setup the connection and the tunnel between the routers is working correctly. We now need the last step. There's no connection to the computers on the other end. What could we have forgotten? (we're testing with two standard configured Win7 machines)

EDIT: Just to clarify the tunnel is working I can ping the router on the other end. I can't access the computers on the other side of that router and vice versa. (It's also possible to access the remotemangement console of the remote router on the LAN IP)