[44080] in North American Network Operators' Group
Re: redistribution
daemon@ATHENA.MIT.EDU (Randy Bush)
Sat Nov 3 17:43:44 2001
From: Randy Bush <randy@psg.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
To: Alex Bligh <alex@alex.org.uk>
Cc: nanog@nanog.org
Message-Id: <E1609VO-0004J9-00@rip.psg.com>
Date: Sat, 03 Nov 2001 14:43:10 -0800
Errors-To: owner-nanog-outgoing@merit.edu
this is getting far more complex than that point warrants.
someone said one should not distribute bgp into igp and igp into bgp.
i tried a simple example where
o there are few non-default routes but they are significant
o there are two routers that have external neighbors, at least one
of which must be an ebgp speaker and the other may be bgp or default
o and there is a third router *in the middle* to which a customer is
attached
the point is
o the router in the middle *must* do dynamic routing, or there will
be a routing loop
o for many reasons, it is likely the middle router will be an igp, not
bgp speaker
o hence very careful redistribution of ebgp to igp, and of igp to bgp
is useful
randy
