SLD
Premium
join:2002-04-17
 ·Comcast
1 edit | Suddenly slowdown to my local datacenter
Last Thursday, I noticed my normally blazing connection to our server about 15 miles from here dropped to as low as 60K/sec. It appears that a Comcast router along the way is dropping packets and I tried opening a ticket with them, but no response thusfar. I ran a pathping - and it seems that hop 7 is a serious problem (I've seen it drop up to 52%). Any ideas to get Comcast to fix this?
Tracing route to codeinfusion.com [38.100.144.199]
over a maximum of 30 hops:
0 CarterPC [192.168.1.2]
1 192.168.1.1
2 * 73.208.80.1
3 ge-2-25-ur01.rosenberg.tx.houston.comcast.net [68.85.249.13]
4 po-13-ar02.bearcreek.tx.houston.comcast.net [68.85.244.41]
5 po-11-ar01.bearcreek.tx.houston.comcast.net [68.85.244.45]
6 po-12-ar01.royalton.tx.houston.comcast.net [68.85.244.50]
7 po-11-ar02.royalton.tx.houston.comcast.net [68.85.244.98]
8 po-17-ar02.greenspoint.tx.houston.comcast.net [68.85.244.130]
9 COMCAST-IP.edge3.Dallas1.Level3.net [4.71.198.42]
10 xe-3-3-0.edge3.Dallas1.Level3.net [4.71.198.41]
11 ae-23-79.car3.Dallas1.Level3.net [4.68.19.69]
12 COGENT-COMM.car3.Dallas1.Level3.net [4.68.110.110]
13 te3-2.mpd01.dfw01.atlas.cogentco.com [154.54.6.57]
14 te4-2.mpd01.iah01.atlas.cogentco.com [154.54.25.98]
15 gi2-0-0.core01.iah01.atlas.cogentco.com [154.54.2.241]
16 gi3-1.core01.iah02.atlas.cogentco.com [66.28.4.114]
17 vl3821.na21.b015437-0.iah02.atlas.cogentco.com [66.250.8.166]
18 38.100.144.193
19 codeinfusion.com [38.100.144.199]
Computing statistics for 475 seconds...
Source to Here This Node/Link
Hop RTT Lost/Sent = Pct Lost/Sent = Pct Address
0 CarterPC [192.168.1.2]
0/ 100 = 0% |
1 0ms 0/ 100 = 0% 0/ 100 = 0% 192.168.1.1
0/ 100 = 0% |
2 8ms 0/ 100 = 0% 0/ 100 = 0% 73.208.80.1
0/ 100 = 0% |
3 9ms 0/ 100 = 0% 0/ 100 = 0% ge-2-25-ur01.rosenberg.tx.houston.comcast.net [68.85.249.13]
0/ 100 = 0% |
4 10ms 0/ 100 = 0% 0/ 100 = 0% po-13-ar02.bearcreek.tx.houston.comcast.net [68.85.244.41]
0/ 100 = 0% |
5 11ms 0/ 100 = 0% 0/ 100 = 0% po-11-ar01.bearcreek.tx.houston.comcast.net [68.85.244.45]
0/ 100 = 0% |
6 11ms 0/ 100 = 0% 0/ 100 = 0% po-12-ar01.royalton.tx.houston.comcast.net [68.85.244.50]
0/ 100 = 0% |
7 12ms 17/ 100 = 17% 17/ 100 = 17% po-11-ar02.royalton.tx.houston.comcast.net [68.85.244.98]
0/ 100 = 0% |
8 14ms 0/ 100 = 0% 0/ 100 = 0% po-17-ar02.greenspoint.tx.houston.comcast.net [68.85.244.130]
0/ 100 = 0% |
9 17ms 0/ 100 = 0% 0/ 100 = 0% COMCAST-IP.edge3.Dallas1.Level3.net [4.71.198.42]
0/ 100 = 0% |
10 22ms 0/ 100 = 0% 0/ 100 = 0% xe-3-3-0.edge3.Dallas1.Level3.net [4.71.198.41]
0/ 100 = 0% |
11 28ms 0/ 100 = 0% 0/ 100 = 0% ae-23-79.car3.Dallas1.Level3.net [4.68.19.69]
0/ 100 = 0% |
12 --- 100/ 100 =100% 100/ 100 =100% COGENT-COMM.car3.Dallas1.Level3.net [4.68.110.110]
0/ 100 = 0% |
13 66ms 0/ 100 = 0% 0/ 100 = 0% te3-2.mpd01.dfw01.atlas.cogentco.com [154.54.6.57]
0/ 100 = 0% |
14 57ms 0/ 100 = 0% 0/ 100 = 0% te4-2.mpd01.iah01.atlas.cogentco.com [154.54.25.98]
0/ 100 = 0% |
15 55ms 2/ 100 = 2% 2/ 100 = 2% gi2-0-0.core01.iah01.atlas.cogentco.com [154.54.2.241]
0/ 100 = 0% |
16 54ms 0/ 100 = 0% 0/ 100 = 0% gi3-1.core01.iah02.atlas.cogentco.com [66.28.4.114]
0/ 100 = 0% |
17 55ms 0/ 100 = 0% 0/ 100 = 0% vl3821.na21.b015437-0.iah02.atlas.cogentco.com [66.250.8.166]
1/ 100 = 1% |
18 57ms 3/ 100 = 3% 2/ 100 = 2% 38.100.144.193
0/ 100 = 0% |
19 55ms 1/ 100 = 1% 0/ 100 = 0% codeinfusion.com [38.100.144.199]
Trace complete. |
|
SolarPup
IT Geek-Dawg
Premium
join:2002-03-07
The Pound
clubs: | Comcast does rate limiting, so these results on their routers may not be true results. Ping times/RTT look great otherwise... |
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K Patterson
Premium,MVM
join:2006-03-12
Columbus, OH | reply to SLD
Hop 7 is not a problem. That router, like many routers on the 'net, has been intentionally configured to give low priority to responding to ping/tracert packets.
Try a speed test to something other that a Cogent site. |
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captain456
@gci.com
| reply to SLD
This is why your datacenter should not rely on cogentco. Since level3 is handing it off to cogentco I am assuming your datacenter either relies cogentco. Dallas has some nice datacenters, with peering and transit going on with a lot of big provides. Are you using a cogentco pipe from theplanet?
I have 6 dedicated servers and would never consider a datacenter that didn't have redundent Tier 1 connections. I guess you get what you pay for that's why cogentco is so cheap. you can get a 100Mbit connection to them for under a grand, or half the price of most tier1 providers.
If you do rely on cogentco you should at least try to get a pipe from someoneelse, anyone else that can become a backup and even handle overflow. |
|
NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
 ·Pacific Bell - SBC
| reply to SLD
Destination reachable, despite |
said by SLD  :Last Thursday, I noticed my normally blazing connection to our server about 15 miles from here dropped to as low as 60K/sec. It appears that a Comcast router along the way is dropping packets and I tried opening a ticket with them, but no response thusfar. I ran a pathping - and it seems that hop 7 is a serious problem (I've seen it drop up to 52%). Any ideas to get Comcast to fix this? This is a problem? Trace route sends a series of ICMP packets to each router between your connection and your destination. As long as all of the packets are passing the "problem" router, and coming back, there is no problem.
Furthermore, you normally get data exchange with the destination using TCP packets, not ICMP packets; so even when the destination does not respond to ICMP, that does not mean there is packet loss.
Consider msn.com:
There is no packet loss, despite the destination not responding to ICMP. See the screen shot.
Speed problems can be caused by a host of different problems; trace route is not the best tool to diagnose a speed problem.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
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NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
| reply to captain456
said by captain456 :
This is why your datacenter should not rely on cogentco...
I have 6 dedicated servers and would never consider a datacenter that didn't have redundent Tier 1 connections...
Cogentco is a Tier 1 network?
»en.wikipedia.org/wiki/Tier_1_network
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
|
captain456
@gci.com | No cogentco is not tier 1 if you thought I said that it was miscommunication |
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SLD
Premium
join:2002-04-17
·Comcast
3 edits | reply to captain456
It isn't Cogent's fault. Like I said, I've had blazing fast connection to the site until Comcast started mucking my speeds. I've done this back and forth with Cogent and they've confirmed it is a problem with Comcast's network. Either that hop 7 or the handoff to Level3. Everyone else visiting our sites are getting very fast speeds. Right now I'm getting a pathetic 100Kb/sec. I get 22Mb/sec to Dallas on SpeedTest.Net which is typical. |
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