[50849] in North American Network Operators' Group
Re: endpoint liveness (RE: Do ATM-based Exchange Points make sense an
daemon@ATHENA.MIT.EDU (Petri Helenius)
Mon Aug 12 02:34:04 2002
Date: Mon, 12 Aug 2002 09:33:27 +0300
From: Petri Helenius <pete@he.iki.fi>
To: Jesper Skriver <jesper@skriver.dk>
Cc: Lane Patterson <lpatterson@equinix.com>,
Mikael Abrahamsson <swmike@swm.pp.se>, nanog@merit.edu
Errors-To: owner-nanog-outgoing@merit.edu
Jesper Skriver wrote:
> Your Cisco router (say a GSR) will go foobar if you use 10/30 seconds
> timers, a IGP topology change, causing a new next-hop interface for
> 100k routes, will cause processes (probably CEF related) to run for so
> long, that you will loose your BGP keepalives, thus loose sessions, and
> everything will go *BOOM* - so please be nice and don't do that without
> real testing.
>
This is the exact reason why you want your liveness to be detected
out of band of the actual routing protocol keepalives which might
also be stuck behind a queue of incoming updates which you need to
read off the socket before you can see the HELLO coming in.
Of course you're toast either way if your interface queues are
large enough and you don't do preferential queueing for BGP.
Pete
