[3762] in North American Network Operators' Group
Re: Customer AS
daemon@ATHENA.MIT.EDU (Avi Freedman)
Mon Aug 19 19:22:58 1996
From: Avi Freedman <freedman@netaxs.com>
To: amb@xara.net (Alex.Bligh)
Date: Mon, 19 Aug 1996 19:02:54 -0400 (EDT)
Cc: curtis@ans.net, amb@xara.net, smd@chops.icp.net, pferguso@cisco.com,
chris@computek.net, tcrowell@gte.net, nanog@merit.edu
In-Reply-To: <199608192229.XAA17476@diamond.xara.net> from "Alex.Bligh" at Aug 19, 96 11:29:35 pm
> Ah. So this was the automation Sean was referring to - not
> accepting more specifics of routes with identical AS paths.
>
> telehouse1#conf t
> Enter configuration commands, one per line. End with CNTL/Z.
> telehouse1(config)#router bgp 5413
> telehouse1(config-router)# neighbor x.x.x.x filter-list 199 in summary-only
>
> ... Pipedream? I think it would actually be implementatable. I see
> Paul F has managed to get himself on the CC list :-)
>
> Alex Bligh
> Xara Networks
I thought of building configs to do that (assuming a filter-list xx in summ)
but it's difficult to tell which sets of contiguous BGP announcements are
being announced un-aggregated in an attempt to direct traffic one way or
another...
Without trying to start any religious fights, I would point out that a
database of what things 'should' look like would be one way to store such
information (about desired/required specificity).
I'll update it this week, but look at http://routes.netaxs.com for a
route-aggregation-suggestion tool that I built last year to see "how bad"
the problem was - or, more specifically, how much space could be saved
by taking compressing contiguous routes with the same next-hop (or head
of the AS-Path list, pick which you prefer - they're 95% the same) at
an exchange point. The page currently has data from April. Stuff in
>= 207/8 is particularly ugly.
Avi
