[10616] in North American Network Operators' Group
Re: weird BGP cisco-ism?
daemon@ATHENA.MIT.EDU (Ravi Chandra)
Fri Jul 11 04:01:23 1997
Date: Fri, 11 Jul 1997 00:51:27 -0700
From: Ravi Chandra <rchandra@cisco.com>
To: matthew@scruz.net
cc: nanog@merit.edu
In cisco.external.nanog you write:
>I have a Cisco 7505 which is advertising about 50 routes to about 40
>peers at mae-west, and a few others. One set of customers has been complaining
>that their connectivity is going away right at that router, and then coming
>back. Narrowed the set of customers down to a single CIDR block, at
>204.147.224.0/20.
>So, some of our peers are claiming that the route is flapping... that's
>weird, we have them all nailed up to static routes... especially the CIDR
>blocks. So I wrote a tool which you can peer a router with, and it watches
>the BGP traffic and prints anything it gets, formatted, to standard out.
>My Cisco is sending fresh advertisements every 10-30 minutes for that route,
>and not for any other of the routes it has, and it appeared to be all the same,
>but on careful examination, it appears that each advertisement reflects a
>change in the MULTI_EXIT_DISC from 0x00000000 to 0x00000014 and then back
>again in the next advertisement.
add a default-metric under router bgp.. I think the source of the
route in the routing table is changing for some reason and the box is
conveying the metric as MED...
--ravi
>What the heck am I seeing here? Is someone's flap damping code seeing the
>repeated advertisements and suppressing me? Is my Cisco going crazy?
>-matthew kaufman
> matthew@scruz.net
