franck at genius.com
Thu Sep 30 22:00:08 UTC 2010
Because the path was broken everytime the bgp session was established and rewriting the routing table with more specific routes?
----- Original Message -----
From: "Randy Bush" <randy at psg.com>
To: "North American Network Operators Group" <nanog at nanog.org>
Sent: Thursday, 30 September, 2010 2:37:43 PM
Subject: Re: BGP next-hop
i was recently bitten by a cousin of this
research router getting an ebgp multi-hop full feed from 18.104.22.168
(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 22.214.171.124/16 and then can not
resolve the next hop. it would not recurse to the default exit.
of course it was solved by
ip route 126.96.36.199 255.255.0.0 42.666.77.11
but i do not really understand in my heart why i needed to do this.
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