Cogent --> Google Public DNS routing issue

Robert Glover robertg at garlic.com
Wed Aug 17 04:09:30 UTC 2011


Hello,

We have noticed that from our Cogent link (as well as from ALL U.S. 
based points we tested via the Cogent Looking Glass: 
http://www.cogentco.com/en/network/looking-glass), traceroutes to 
8.8.8.8 and 8.8.5.5 all seem to go over to Europe:

TRACE from Los Angeles to 8.8.4.4
1 gi2-6.99.mpd03.lax01.atlas.cogentco.com (66.28.3.81) 0.514 ms 0.332 ms
2 te0-0-0-6.ccr22.lax01.atlas.cogentco.com (154.54.28.145) 0.401 ms 0.518 ms
3 te0-3-0-6.ccr22.iah01.atlas.cogentco.com (154.54.3.185) 36.538 ms 
te0-2-0-5.ccr22.iah01.atlas.cogentco.com (154.54.27.18) 36.449 ms
4 te0-0-0-2.ccr22.atl01.atlas.cogentco.com (154.54.5.93) 63.200 ms 
te0-2-0-7.ccr22.atl01.atlas.cogentco.com (66.28.4.89) 62.909 ms
5 te0-1-0-2.ccr22.dca01.atlas.cogentco.com (154.54.28.230) 62.985 ms 
te0-0-0-7.ccr22.dca01.atlas.cogentco.com (154.54.28.221) 62.894 ms
6 te0-5-0-6.ccr22.jfk02.atlas.cogentco.com (154.54.42.30) 69.434 ms 
te0-5-0-2.ccr22.jfk02.atlas.cogentco.com (154.54.42.26) 69.229 ms
7 te0-3-0-2.ccr22.lon13.atlas.cogentco.com (154.54.30.22) 144.224 ms 
te0-2-0-2.ccr22.lon13.atlas.cogentco.com (154.54.30.133) 146.474 ms
8 te8-1.mpd02.lon01.atlas.cogentco.com (154.54.57.182) 143.890 ms 
te7-1.mpd02.lon01.atlas.cogentco.com (154.54.57.178) 146.320 ms
9 ldn-b4-link.telia.net (213.248.70.237) 145.967 ms 145.872 ms
10 80.91.247.93 (80.91.247.93) 155.170 ms ldn-bb1-link.telia.net 
(213.155.130.46) 145.971 ms
11 ldn-b3-link.telia.net (213.155.133.33) 143.909 ms 80.91.249.170 
(80.91.249.170) 146.213 ms
12 google-ic-126258-ldn-b3.c.telia.net (213.248.67.66) 146.158 ms 146.291 ms
13 64.233.175.25 (64.233.175.25) 146.166 ms 64.233.175.27 
(64.233.175.27) 144.256 ms
14 209.85.253.92 (209.85.253.92) 146.435 ms 146.401 ms
15 72.14.232.134 (72.14.232.134) 150.128 ms 66.249.95.173 
(66.249.95.173) 152.591 ms
16 209.85.252.83 (209.85.252.83) 149.993 ms 209.85.251.231 
(209.85.251.231) 152.270 ms
17 209.85.243.85 (209.85.243.85) 152.514 ms 152.332 ms
18 google-public-dns-b.google.com (8.8.4.4) 152.436 ms 152.299 ms

The routes from our backup carrier stay state-side and result in ~30ms 
ping times.  Through Cogent, the ping times are around ~164ms

What is going on here?  Can someone from Cogent chime in on this?

-Robert





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