Best practices IPv4/IPv6 BGP (dual stack)

Ryan Wilkins ryan at
Fri May 2 20:21:09 UTC 2014

> 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?
> 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.
> 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?
> Thanks in advance,
> DJ

For what it’s worth, my AboveNet and Cogent BGP peerings are v4 for v4 routes and v6 for v6 routes.  Two separate sessions to each carrier.

While I don’t have any BGP speaking IPv6 customers yet, I would set up this same way to keep the two protocols apart from each other.

Ryan Wilkins

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