[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [RRG] BGP Graceful Restart (was Re: Geoff Huston's article ...)
On Jun 20, 2007, at 11:20 AM, Geoff Huston wrote:
ksriram@nist.gov wrote:
For the purpose of damping BGP or reducing its churn, another
important tool that should be quite useful is the BGP graceful
restart (BGP-GR) mechanism (RFC 4724).
All depends on what you see as being the major factors that
contribute to the BGP processing load in today's routing
environment. Graceful restart is very effective, and it should be
deployed ubiquitously, but from where I sit in the routing mesh the
occasional spike I see in the update rate does not strike me as
being a major contributor to the BGP update rate. Of course this is
a subjective rather than a qualitative response and your mileage in
your neck of the woods may vary!
As Geoff points out, the best that GR could do is to alleviate some
churn due to software restarts. Real link failures or hardware
failures are still going to result in churn.
There's also a reliability and confidence issue with GR. The
presumption with GR is that a router advertising its restart
capabilities will have a forwarding plane that will continue to
reliably forward during a failure in the control plane. If it does
not do this, then it will either blackhole or misroute traffic, which
is obviously not good. Many carriers don't yet have the confidence
is the implementations to put this into production. Hopefully, of
course, this will change. However, I don't think we should wait for it.
Regards,
Tony
--
to unsubscribe send a message to rrg-request@psg.com with the
word 'unsubscribe' in a single line as the message text body.
archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg