nanog mailing list archives

Re: Cogent latency / congestion


From: Mike Tancsa <mike () sentex net>
Date: Mon, 20 Aug 2007 16:11:44 -0400


At 03:54 PM 8/20/2007, Dan Armstrong wrote:
We're going crazy up here, I'm trying to nail down where exactly the problem is - We don't use Cogent anywhere, but we're having terrible problems with Bell and many sites in Europe...

Bell uses Cogent in a large way. The second traceroute was from an IP in their AS (577) out. I am prepending out Cogent, but Bell does everything it can not to use Teleglobe so I am having problems influencing their routes to come back that way. They also have a very odd path out of Chicago. This is from a site in Toronto (source IP in AS577) back to me peering with Cogent's router in Toronto... Toronto, Chicago, Kansas, Texas, Washington, Boston, Albany, Toronto. Thats quite the milk run. Usually its Toronto, Chicago, Toronto.

% traceroute -f 6 -q1 199.212.134.3
traceroute to 199.212.134.3 (199.212.134.3), 64 hops max, 40 byte packets
 6  64.230.229.5 (64.230.229.5)  4.846 ms
 7  64.230.242.97 (64.230.242.97)  4.030 ms
 8  64.230.147.14 (64.230.147.14)  14.213 ms
 9  206.108.103.142 (206.108.103.142)  14.216 ms
10  p13-0.core01.ord01.atlas.cogentco.com (154.54.11.29)  101.348 ms
11  te3-1.mpd01.ord01.atlas.cogentco.com (154.54.1.206)  102.507 ms
12  t2-4.mpd01.mci01.atlas.cogentco.com (154.54.2.233)  108.993 ms
13  t4-2.mpd01.iah01.atlas.cogentco.com (154.54.5.221)  108.496 ms
14  t2-2.mpd01.dca01.atlas.cogentco.com (154.54.2.145)  110.221 ms
15  t8-2.mpd01.bos01.atlas.cogentco.com (154.54.1.105)  129.529 ms
16  g2-0-0.core01.bos01.atlas.cogentco.com (154.54.2.213)  108.507 ms
17  p13-0.core01.alb02.atlas.cogentco.com (154.54.7.41)  116.526 ms
18  p14-0.core01.yyz01.atlas.cogentco.com (66.28.4.218)  118.463 ms
19  v3491.mpd01.yyz01.atlas.cogentco.com (154.54.5.78)  217.912 ms
20  v3492.mpd01.yyz02.atlas.cogentco.com (154.54.5.82)  225.491 ms
21  sentex.demarc.cogentco.com (38.104.158.78)  217.134 ms
22  i3-vl-814 (67.43.129.242)  65.576 ms
23  shell1 (199.212.134.3)  66.221 ms


        ---Mike





Mike Tancsa wrote:



Does anyone have any details about the Cogent outage that started this morning (9am GMT-400) and is still continuing ? If its a fibre cut between Montville (NJ?) and Cleveland OH (http://status.cogentco.com/) why is it so bad in Chicago and Albany locations ? Is there really that little excess capacity ?

My connection out of Toronto is pretty bad via Albany

 3  g8-22.mpd01.yyz02.atlas.cogentco.com (38.104.158.77)  7.470 ms
6.754 ms  6.481 ms
 4  v3493.mpd01.yyz01.atlas.cogentco.com (154.54.5.85)  6.981 ms
6.730 ms  6.984 ms
5 g2-0-0-3490.core01.yyz01.atlas.cogentco.com (154.54.5.73) 6.482 ms 7.175 ms 5.974 ms
 6  p4-0.core01.alb02.atlas.cogentco.com (66.28.4.217)  105.954 ms
112.055 ms  111.426 ms
 7  p6-0.core01.bos01.atlas.cogentco.com (154.54.7.42)  115.413 ms
117.090 ms  113.816 ms

and Bell's through Chicago is even worse

6  64.230.229.5 (64.230.229.5)  12.572 ms  36.983 ms  200.187 ms
 7  64.230.242.97 (64.230.242.97)  4.685 ms  5.439 ms  3.645 ms
 8  64.230.147.14 (64.230.147.14)  14.351 ms  15.344 ms  14.387 ms
 9  206.108.103.142 (206.108.103.142)  14.374 ms  14.280 ms  14.255 ms
10 p13-0.core01.ord01.atlas.cogentco.com (154.54.11.29) 156.616 ms * 142.150 ms
11  te3-1.mpd01.ord01.atlas.cogentco.com (154.54.1.206)  135.199 ms
138.900 ms *
12  t2-4.mpd01.mci01.atlas.cogentco.com (154.54.2.233)  152.292 ms
149.956 ms  148.095 ms
13  t4-2.mpd01.iah01.atlas.cogentco.com (154.54.5.221)  149.047 ms
150.556 ms  151.232 ms

        ---Mike


--------------------------------------------------------------------
Mike Tancsa,                                      tel +1 519 651 3400
Sentex Communications,                            mike () sentex net
Providing Internet since 1994                    www.sentex.net
Cambridge, Ontario Canada                         www.sentex.net/mike


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