> I would recommend against speaking OSPF to routers administered by > a different party. If both sides support BGP use BGP instead of OSPF. If > you can't speak BGP to the other party use one OSPF instance per party.
I'd just like to add that filtering can be done in any distance-vector protocol. If you prefer an IGP (so you can avoid messing with private AS numbers), this can be done in RIPv2/RIPng, EIGRP, and Babel. But I agree with Jan, BGP is a good choice. -- Juliusz
