nanog mailing list archives

Re: endpoint liveness (RE: Do ATM-based Exchange Points make sense an ymore?)


From: Petri Helenius <pete () he iki fi>
Date: Mon, 12 Aug 2002 09:33:27 +0300


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


Current thread: