> Section 9.1.2.1 of RFC 4271 seems to address this. > A few points from that section: > - The BGP NEXT_HOP can not recursively resolve (directly or indirectly) > through the BGP route. > - Only the longest matching route should be considered when resolving the > BGP NEXT_HOP. > - Do not consider feasible routes that would become unresolvable if they > were installed.
There are 2 ways of reading that.. Perhaps i'll go and look at the it in more details. I'm trying to think of a scenario where following this or something similar would break it: - Don't use BGP prefixes to resolve next-hop. - You can use 0/0 or any route with a lower administrative distance to resolve the next-top. With that in mind, I wonder if it works with Juniper (ad = 170 vs 20 from memory)..