nanog mailing list archives

Re: Did your BGP crash today?


From: Joel Jaeggli <joelja () bogus com>
Date: Sun, 29 Aug 2010 10:13:44 -0700

On 8/27/10 1:07 PM, Mike Gatti wrote:
where's the change management process in all of this. 
basically now we are going to starting changing things that can 
potentially have an adverse affect on users without letting anyone know
before hand .... Interesting concept.

BGP is transitive, change management is not. you have a change
management process, your peer might integrate into that but have their
own, your peer's peers almost certainly do not.

Every time a wet-behind-the-ears network engineer connects a bgp speaker
to the edge of the network it's an experiment in the the stability of
the Internet.

This on the fact of it seems like a quite reasonable experiment, which
should have worked, except that it happened to tickle a bug...


On Aug 27, 2010, at 3:33 PM, Dave Israel wrote:


On 8/27/2010 3:22 PM, Jared Mauch wrote:
When you are processing something, it's sometimes hard to tell if something
just was mis-parsed (as I think the case is here with the "missing-2-bytes")
vs just getting garbage.  Perhaps there should be some way to "re-sync" when
you are having this problem, or a parallel "keepalive" path similar to
MACA/MCAS/MIDCAS/TCAS between the devices to talk when something bad is
happening.

I know it wasn't there originally, and isn't mandatory now, but there is
an MD5 hash that can be added to the packet.  If the TCP hash checks
out, then you know the packet wasn't garbled, and just contained
information you didn't grok.  That seems like enough evidence to be able
to shrug and toss the packet without dropping the session.

-Dave




=+=+=+=+=+=+=+=+=+=+=+=+=
Mike Gatti  
ekim.ittag () gmail com
=+=+=+=+=+=+=+=+=+=+=+=+=








Current thread: