[130274] in North American Network Operators' Group
Re: BGP next-hop
daemon@ATHENA.MIT.EDU (Randy Bush)
Thu Sep 30 17:37:56 2010
Date: Fri, 01 Oct 2010 06:37:43 +0900
From: Randy Bush <randy@psg.com>
To: North American Network Operators Group <nanog@nanog.org>
In-Reply-To: <1285862653.30784.23.camel@angel>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
i was recently bitten by a cousin of this
research router getting an ebgp multi-hop full feed from 147.28.0.1
(address is relevant)
it is on a lan with a default gateway 42.666.77.11 (address not
relevant), so it has
ip route 0.0.0.0 0.0.0.0 42.666.77.11
massive flapping results.
it seems it gets the bgp route for 147.28.0.0/16 and then can not
resolve the next hop. it would not recurse to the default exit.
of course it was solved by
ip route 147.28.0.0 255.255.0.0 42.666.77.11
but i do not really understand in my heart why i needed to do this.
randy
