The BGP connection collision detection mechanism only applies where two
parallel *TCP* connections between a pair of BGP speakers might be formed.
IMO, the first sentence of section 6.8 does scope the collision detection
mechanism to a TCP connection (src/dst IP, etc..), thereby requiring an
implementation to first consider the TCP (and lower layer) stuff before
looking "deeper".
Cisco does behave correctly in this configuration so you shouldn't have a
problem unless IP src/dst pair are the same between a single set of BGP
speakers.
-danny
> This should be an easy question:
>
> Can I safely maintain a two EBGP between two routers (A and B) if
> I use different interfaces on each router? This appears to work in
> the lab, though the RFC (quoted below) implies it might be unsafe. What
> I am worrying about is one connection flapping, and in the process
> of the flap, closing the other connection. My reading of this
> implies there are circumstances where this can happen.
>
> In my view, with EBGP in a non-multihop environment, one should be
> safe using the link layer source and destination as additional
> discriminators as to whether the connection should be closed,
> as in this instance, it is, contrary to the RFC, not "clear" that
> additional connections should be closed, as they may be set up
> deliberately to maintain peering over multiple fabrics for resilience
> (for instance). Does anyone know if this is the actual Cisco
> implementation? (which is all I'm interested in right now)
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:07 EDT