On May 2, 2014, at 12:44 PM, Deepak Jain <dee...@ai.net> wrote: > > Between peering routers on a dual-stacked network, is it considered best > practices to have two BGP sessions (one for v4 and one for v6) between them? > Or is it better to put v4 in the v6 session or v6 in the v4 session?
Separate v4 and v6 sessions are the best practice. It is possible to have a single-protocol outage in which case you either take out the other protocol unnecessarily or you black-hole traffic. > According to docs, obviously all of these are supported and if both sides are > dual stacked, even the next-hops don't need to be overwritten. Mostly true, but implementations vary and YMMV vendor to vendor and in some cases, model and/or software version to model and/or software version. Two sessions always works and unless you are somehow resource-constrained on sessions is really the simplest, easiest to manage, cleanest way to do things. > Is there any community-approach to best practices here? Any FIB weirdness > (e.g. IPv4 routes suddenly start sucking up IPv6 TCAM space, etc) that > results with one solution over the other? See above for BCP. As to the rest, in my experience, the answers vary (see above). Owen
