nanog mailing list archives

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


From: Jesper Skriver <jesper () skriver dk>
Date: Mon, 12 Aug 2002 03:01:23 +0200


On Fri, Aug 09, 2002 at 03:22:00PM -0700, Lane Patterson wrote:

BGP keepalive/hold timers are configurable even down to granularity of
link or PVC level keepalives, but for session stability reasons, it
appears that most ISPs at GigE exchanges choose not to tweak them down
from the defaults.  IIRC, Juniper is 30/90 and Cisco is 60/180.  My
gut feel was that even something like 10/30 would be reasonable, but
nobody seems compelled that this is much of an issue.

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.

/Jesper

-- 
Jesper Skriver, jesper(at)skriver(dot)dk  -  CCIE #5456
Senior network engineer @ AS3292, TDC Tele Danmark

One Unix to rule them all, One Resolver to find them,
One IP to bring them all and in the zone to bind them.


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