nanog mailing list archives

Re: is something weird going on with cox, level3, and/or cogent


From: Mel Beckman <mel () beckman org>
Date: Mon, 13 Feb 2017 03:45:36 +0000

It looks like one or more circuits are down, so you're seeing asymmetrical routing over congested paths in one 
direction. 

-mel via cell

On Feb 12, 2017, at 7:14 PM, Miles Fidelman <mfidelman () meetinghouse net> wrote:

Hi Folks,

I'm visiting AZ, and seeing some really really poor performance accessing some of our servers via Cox broadband.  The 
folks at Cox technical support are useless - all they say is "well you're on a DOCSIS 2 modem."  Meanwhile, 
everything I'm seeing is several hops upstream of the local segment - and all that Cox level2 tech support will say 
is "if there was a backbone problem, our backbone people would have dealt with it."

I'm having problems reaching both our own server, and sites like google, facebook, windows update.

Traceroutes to and from our server are illustrative - note that for most of the past week, the average ping time was 
85msec. Now we're seeing this:

From 98.177.135.186 - the public IP address on Cox's local broadband service.
To 107.154.13.58 (ntcorp.server - one of our servers, sitting in a Tierpoint data center, near Boston)
traceroute to ntcorp.com (207.154.13.58), 64 hops max, 52 byte packets
1  10.128.128.1 (10.128.128.1)  199.893 ms  75.319 ms  27.295 ms
2  100.127.69.178 (100.127.69.178)  38.710 ms  40.075 ms  43.598 ms
3  72.215.229.22 (72.215.229.22)  39.674 ms  201.368 ms *
4  lag-157.bear2.phoenix1.level3.net (4.28.82.53)  686.499 ms 1837.141 ms  16.273 ms
5  ae-1-60.edge1.losangeles6.level3.net (4.69.144.16)  35.498 ms 964.377 ms *
6  ae-3-80.edge1.losangeles6.level3.net (4.69.144.144)  551.760 ms  525.014 ms
   ae-1-60.edge1.losangeles6.level3.net (4.69.144.16)  2061.191 ms
7  be3036.ccr41.lax04.atlas.cogentco.com (154.54.14.129)  847.778 ms  87.601 ms  71.504 ms
8  be2965.ccr22.lax01.atlas.cogentco.com (154.54.45.1)  79.060 ms  225.647 ms
   be2964.ccr21.lax01.atlas.cogentco.com (154.54.44.77)  60.306 ms
9  * be2931.ccr21.phx02.atlas.cogentco.com (154.54.44.85) 2264.071 ms  185.180 ms
10  be2929.ccr21.elp01.atlas.cogentco.com (154.54.42.66)  61.208 ms
   be2930.ccr21.elp01.atlas.cogentco.com (154.54.42.78)  386.149 ms  1278.868 ms
11  be2928.ccr22.iah01.atlas.cogentco.com (154.54.30.161)  384.136 ms
   be2927.ccr41.iah01.atlas.cogentco.com (154.54.29.221) 2339.833 ms  615.415 ms
12  be2690.ccr42.atl01.atlas.cogentco.com (154.54.28.129)  233.061 ms
   be2687.ccr41.atl01.atlas.cogentco.com (154.54.28.69)  87.902 ms
   be2690.ccr42.atl01.atlas.cogentco.com (154.54.28.129)  861.159 ms
13  be2113.ccr42.dca01.atlas.cogentco.com (154.54.24.221)  998.858 ms
   be2112.ccr41.dca01.atlas.cogentco.com (154.54.7.157)  249.930 ms *
14  be2807.ccr42.jfk02.atlas.cogentco.com (154.54.40.109)  768.461 ms
   be2806.ccr41.jfk02.atlas.cogentco.com (154.54.40.105)  136.772 ms
   be2807.ccr42.jfk02.atlas.cogentco.com (154.54.40.109)  288.225 ms
15  be2094.ccr21.bos01.atlas.cogentco.com (154.54.30.14)  271.736 ms  166.224 ms
   be2096.ccr22.bos01.atlas.cogentco.com (154.54.30.42)  565.015 ms
16  te0-4-1-7.agr22.bos01.atlas.cogentco.com (154.54.80.34) 1944.479 ms
   te0-4-1-6.agr22.bos01.atlas.cogentco.com (154.54.80.10) 149.803 ms
   te0-4-1-6.agr21.bos01.atlas.cogentco.com (154.54.47.230) 897.115 ms
17  te0-0-2-0.nr11.b000254-0.bos01.atlas.cogentco.com (154.24.9.82)  107.207 ms
   te0-0-2-1.nr11.b000254-0.bos01.atlas.cogentco.com (154.24.9.78)  295.881 ms  185.453 ms
18  38.122.127.18 (38.122.127.18)  115.652 ms  461.168 ms  615.526 ms
19  207.154.0.57 (207.154.0.57)  1871.023 ms  1987.832 ms 2165.248 ms
20  server1.ntcorp.com (207.154.13.58)  587.560 ms  263.328 ms 333.542 ms


Traceroute in the reverse direction:
1  207.154.13.47 (207.154.13.47)  0.000 ms  0.000 ms  0.000 ms
2  * * *
3  h130.207.190.173.static.ip.windstream.net (173.190.207.130) 0.000 ms  0.000 ms  0.000 ms
4  xe1-2-0-0.cr01.cley01-oh.us.windstream.net (40.128.250.166) 12.000 ms  12.000 ms  12.000 ms
5  et11-0-0-0.cr01.chcg01-il.us.windstream.net (40.128.248.71) 20.000 ms  20.000 ms  20.000 ms
6  10gigabitethernet4-1.core1.chi1.he.NET (206.223.119.37)  72.001 ms  20.000 ms  16.000 ms
7  chgobbrj01pos010100.r2.ch.cox.net (68.105.30.193)  20.000 ms 20.000 ms  20.000 ms
8  chnddsrj01-ae1.0.rd.ph.cox.net (68.1.5.211)  72.001 ms  72.001 ms  72.001 ms
9  * * *
10  * * *
11  * * *
<snip>
30  * * *
<looks like a lot of the later hops don't respond to pings>

Two things jump out at me:
1. The rather large number of hops from cox to ntcorp - with high delays  from several nodes in both the level3 and 
cogent networks.
2. That there's a rather more direct path from the datacenter to cox, that shows up in the reverse direction.

Some kind of routing or peering issue, perhaps?  (And I also note the earlier string of messages regarding youtube 
streaming problems - that also seemed to involve cox and level3.

Thanks for any insight (and better, for any fixes!).

Miles Fidelman




-- 
In theory, there is no difference between theory and practice.
In practice, there is.  .... Yogi Berra



Current thread: