AS7170 flaps and resulting non-event
Craig A. Haney
craig at seamless.kludge.net
Thu Dec 2 09:21:15 UTC 1999
John,
AT&T-DISC is an AT&T Network that is specifically for DREN/DISC DoD
Government use.
It is not their public/commercial IP service offering.
What is DREN: http://www.hpcmo.hpc.mil/Htdocs/DREN/dren-def.html
DREN HOMEPAGE: http://www.hpcmo.hpc.mil/Htdocs/DREN/
What is DISC: http://www.hpcmo.hpc.mil/Htdocs/DREN/disc-sow-new.html
For a while now I understand this network is working with a skeleton
operations crew and none of the original architects have been there
for a long time. And some of the Merit folks that were under contract
to AT&T DISC as advisors also have left Merit recently.
It is probally best to take up any issues you have with the DISC HELP
DESK information available at:
http://www.hpcmo.hpc.mil/Htdocs/DREN/disc-help.html
They are located either in Vienna, VA off Gallows Rd (right near
MAE-EAST) or Oakton VA (Down Rt 123 - again near MAE-EAST).
and/or also take up the issue with the Technical Advisory Panel at
the same time:
And I see that this list is out of date.
http://www.arl.mil/HPCMP/DREN/program-pocs.html
hope this helps you getting your concern resolved.
-craig
23:22 -0800 12/01/1999, John Todd wrote:
>Starting on the 19th of this month, the Merit routing report shows
>that AT&T-DISC(AS7170) is having some serious flapping issues with
>the Merit route server at the MAE-East (ten million updates in a
>day, as an example.) Among other things, I'm interested if these
>flaps are being made to all peers of AS7170 at the MAE-East. If
>that is the case, then nobody has noticed, or nobody cares, or
>nobody has raised it in a public forum yet. If the silence has been
>caused by one of the first two situations, I'm interested in which
>is the true reason that there has been no hue and cry over this
>abnormal number of route insertions/removals.
>
>
>A few questions and items to chew on:
> 1: Is this something that anyone other than Merit is noticing?
>Could it be that AS7170 just doesn't have that many peers, or that
>the routes are flapping only to Merit's route server?
> 2: Is this just being dampened to the point where nobody notices?
> 3: Is the silence on this issue somehow indicative of the
>increased speed/memory of core routers in the North American and
>other routing structures? [main point] If so, then this changes
>some arguments about who and why one will/will not peer, as well as
>dragging the corpse of "Sprint filtering" out of the grave.[/main
>point]
> 4: Am I just reading this data incorrectly? I don't have a direct
>peer with 7170 anywhere, so I can't look at my own records for
>double-checking.
>
>
>Side notes:
> A: This isn't AT&T's only AS number - they have two others (7018
>and 5075) that seem to be used for quite a few announcements. In
>fact, 7170 may not be the "primary" AS for AT&T - again, I don't
>have a crystal ball to see how they structure their announcements
>across the multiple AS'es.
> B: It's not easily possible for me to find which routes were
>flapping; could this be just a few routes out of the N that 7170
>announces? (See
>http://www.merit.edu/~ipma/cooked/routing_table/view_in/mae-east/mae-e
>ast.7170.view.991128 for an exhaustive list of 7170's routes to
>Merit on the 28th) If it's only a few of the routes, then perhaps
>dampening by peers simply quashed the rogue networks into oblivion
>without anyone noticing that these few routes were missing.
> C: Could this be related?
>http://www.infoworld.com/cgi-bin/displayStory.pl?99121.icatt.htm I
>don't think so, but it's an interesting note nonetheless. I don't
>see how DNS could be attached to the route flaps, but again I don't
>have a crystal ball into AT&T's network.
>
>I've included selected sections from Merit's daily route flap mail.
>To see a complete list of the messages, browse to
>http://www.merit.net/mail.archives/html/routing-problems/ for more
>detail.
>
>Largest Sources of BGP Instability
>----------------------------------
>(announcements + withdraws = total)
>
>Dec 01: 1. AT&T-DISC (AS7170) at Mae-East 10432535 + 36800 =
>10469335 BGP prefix updates
>Nov 30: 1. AT&T-DISC (AS7170) at Mae-East 10432535 + 36800 =
>10469335 BGP prefix updates
>Nov 29: 1. AT&T-DISC (AS7170) at Mae-East 11122216 + 16465 =
>11138681 BGP prefix updates
>Nov 28: 1. AT&T-DISC (AS7170) at Mae-East 10256555 + 17732 =
>10274287 BGP prefix updates
>Nov 27: 1. AT&T-DISC (AS7170) at Mae-East 9882016 + 23527 = 9905543
>BGP prefix updates
>.
>. [similar results in here]
>.
>Nov 19: 1. AT&T-DISC (AS7170) at Mae-East 2462647 + 93171 = 2555818
>BGP prefix updates
>
>[AT&T-DISC does not show up in the mail from the 18th or 17th,
>leading me to think these flaps started during the measured interval
>reported on the 19th.]
>
>---
>JT
>jtodd at loligo.com
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