Best practices IPv4/IPv6 BGP (dual stack)

Laszlo Hanyecz laszlo at
Fri May 2 19:52:24 UTC 2014

Two different sessions using two different transport protocols.  The v4 BGP session should have address family v6 disabled and vice versa.  Exchange v4 routes over a v4 TCP connection, exchange v6 routes over a v6 TCP connection.  Just treat them as independent protocols. 


On May 2, 2014, at 7:44 PM, Deepak Jain <deepak at> 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?
> 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

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