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Date: Wed, 2 Jun 1999 11:02:42 -0700
To: mgates@dast.nlanr.net
From: "David A. Guevara" <dguevara@mail.arc.nasa.gov>
Subject: Re: route from hydra-atm1.colorado.edu -> jsimpson-h.gsfc.nasa.gov
Cc: vbns-eng@mci.net, dast@nlanr.net, bill@wizard.nasa.atd.net,
hammond@solarz.Colorado.EDU
Content-Length: 4695
mark --
the last time this connection was "working" was back in late
february, early march. vbns might be able to provide
some input with regards to the additional router in our path.
I'll cc a copy of this message to their engineering group.
-- david
At 10:31 AM -0700 6/2/99, Mark Gates wrote:
>Hi Anne and David,
>
>I've been investigating the route that you seem to be using. It is very
>peculiar to me. Do you know what dates you started having problems
>between the machines?
>
>I would say the problem is not congestion but routing. The two things
>that looked odd to me are:
>
> 1) The RTO router that is listed on both traceroutes. RTO is Los
>Angeles, and why your packets would be going through there is a mystery
>to me. They should go directly between Chicago (DNG) and Denver (DNJ)
>routers.
>
> 2) Looking at various round-trip-time and traffic statistics, it seems
>there was a definite change in the network on May 20th, 8am UTC. The
>round-trip-time between Denver and Chicago-based institutions jumped
>from 20ms to 40ms. There doesn't appear to be any traffic going directly
>from the Chicago (DNG) router to the Denver (DNJ) router.
>
>I am going to have the NLANR engineering services group look more at
>this and hopefully discover and fix whatever routing is broken in the
>network. Someone from there may contact you directly if they need more
>information. You may still contact me also.
>
> -mark
>
>
>Anne Hammond wrote:
>>
>> Hi,
>>
>> This message below from David Guevara of NASA NREN
>>
>> Would you be able to help in analyzing this slowdown?
>>
>> Anne M. Hammond Anne.Hammond@Colorado.EDU
>> Network/UNIX Admin 303-492-5578 (FAX -5325)
>> JILA / University of Colorado at Boulder
>> Boulder, CO 80309-0440
>>
>> ----- Begin Included Message -----
>>
>> >From dguevara@mail.arc.nasa.gov Tue Jun 1 08:59:02 1999
>> Mime-Version: 1.0
>> Content-Type: text/plain; charset="us-ascii"
>> Date: Tue, 1 Jun 1999 07:58:54 -0700
>> To: "Anne M. Hammond" <hammond@solarz.Colorado.EDU>
>> From: "David A. Guevara" <dguevara@mail.arc.nasa.gov>
>> Subject: Re: route from hydra-atm1.colorado.edu -> jsimpson-h.gsfc.nasa.gov
>> Cc: bill@wizard.nasa.atd.net, mitchell@jila.Colorado.EDU,
>> litvanyi@spot.Colorado.EDU, hammond@hydra.colorado.edu,
>> brummell@hydra.colorado.edu, dguevara@mail.arc.nasa.gov
>> Content-Length: 1929
>>
>> anne --
>>
>> the route between hydra-atm1 and jsimpson-h is back up. there seems
>> to be a congestion problem. currently our rtt is running about 104ms
>> (approximately twice the value we had at the beginning of this project).
>> I think the problem lies with vBNS. See below for traceroutes from
>> hydra-atm1 and jsimpson-h:
>>
>> hydra <~>traceroute jsimpson-h.gsfc.nasa.gov
>> traceroute to jsimpson-h.gsfc.nasa.gov (169.154.161.43), 30 hops max, 40
>> byte pa
>> ckets
>> 1 198.11.22.25 (198.11.22.25) 1 ms 1 ms 1 ms
>> 2 204.131.62.38 (204.131.62.38) 3 ms 3 ms 3 ms
>> 3 cs-atm0-0-14.rto.vbns.net (204.147.130.117) 33 ms 33 ms 33 ms
>> 4 cs-atm0-0-13.dng.vbns.net (204.147.129.145) 81 ms 204 ms 81 ms
>> 5 204.147.128.198 (204.147.128.198) 82 ms 82 ms 83 ms
>> 6 gsfc-chi.nren.nasa.gov (198.10.64.49) 97 ms 97 ms 97 ms
>> 7 192.12.123.42 (192.12.123.42) 98 ms 98 ms 98 ms
>> 8 rtr-900-giga-a.gsfc.nasa.gov (169.154.32.3) 98 ms 98 ms 98 ms
>> 9 * jsimpson-h.gsfc.nasa.gov (169.154.161.43) 100 ms 100 ms
>>
>> jsimpson% /etc/traceroute hydra-atm1.colorado.edu
>> traceroute to hydra-atm1.colorado.edu (198.11.22.12), 30 hops max, 96 byte
>> packe
>> ts
>> 1 169.154.161.1 (169.154.161.1) 6.397 ms 7.808 ms 5.467 ms (6.0/6.000)
>> 2 rtr-atm-a.gsfc.nasa.gov (169.154.1.1) 8.553 ms 8.924 ms 11.023 ms
>> (8.0/9.
>> 000)
>> 3 192.12.123.41 (192.12.123.41) 9.189 ms 5.739 ms 7.83 ms (7.0/7.000)
>> 4 chi-gsfc.nren.nasa.gov (198.10.64.50) 20.339 ms 22.183 ms 22.424 ms
>> (22.0
>> /21.333)
>> 5 204.147.128.197 (204.147.128.197) 21.977 ms 23.711 ms 23.756 ms
>> (23.0/22.
>> 333)
>> 6 cs-atm0-0-12.rto.vbns.net (204.147.129.146) 69.767 ms 72.649 ms
>> 69.713 ms
>> (69.0/70.000)
>> 7 cs-atm0-0-14.dnj.vbns.net (204.147.130.118) 99.653 ms 101.246 ms
>>105.729
>> ms (101.0/101.667)
>> 8 204.131.62.37 (204.131.62.37) 103.403 ms 106.348 ms 104.908 ms
>> (104.0/104
>> .333)
>> 9 hydra-atm1.Colorado.EDU (198.11.22.12) 103.892 ms 104.416 ms 107.273
>> ms (
>> 104.0/104.667)
>>
>> ----- End Included Message -----
>
>--
>Mark Gates 139 ACB
>NLANR applications support 217-244-7959
>http://www.ncsa.uiuc.edu/People/mgates mgates@nlanr.net
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