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

Mon Aug 12 01:01:23 UTC 2002

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.