[ale] OT: Comcast'ers

Fri May 26 18:52:40 EDT 2006

On Fri, May 26 2006 14:39, Jim Popovitch wrote:
>
> Open up a terminal session and mtr to www.test.com.   Notice any
> significant packetloss inside of Comcast's Atlanta headend?
>
> I consistently see ~15% loss at
> 10g-9-3-ur01.B0atlanta.ga.atlanta.comcast.net.  Anyone else?
>

Thanks for the pointer to the new utility, first off.  That's pretty damn 
snazzy.

Interestingly enough, it worked and ran the first time, okay.  However, the 
data that I am getting from it is nowhere near accurate.  After four pings 
or so, it would appear that I am blocked from any IMCP requests.  mtr, 
ping, and traceroute do not work unless I restart the cable modem or wait 
several minutes.  That is *so* annoying.  Is there some rule against that 
type of diagnostic usage?

Anyway, I can get about 20 packets out before ping appears to become blocked 
for whatever reason, but when it is working, I am getting errors at the 
following two nodes:

10g-9-1-ur01.D7decatur.ga.atlanta.comcast.net
10g-9-4-ar01.D1stonemtn.ga.atlanta.comcast.net

Here is one 'mtr' run:
fd0man at fd0man-laptop:~$ mtr -rc 4 www.test.com
HOST: fd0man-laptop               Loss%   Snt   Last   Avg  Best  Wrst StDev
  1. 192.168.0.1                   0.0%     4    0.8   1.0   0.8   1.6   0.4
  2. 73.62.36.1                    0.0%     4    8.9  11.9   8.9  20.3   5.6
  3. GE-1-1-ur01.D6decatur.ga.atl  0.0%     4   10.7  10.0   9.2  10.7   0.6
  4. 10g-9-1-ur01.D7decatur.ga.at  0.0%     4   11.1  10.2   9.0  11.1   0.9
  5. 10g-9-4-ar01.D1stonemtn.ga.a 50.0%     4   11.0  19.0  11.0  27.0  11.3
  6. 12.124.64.21                  0.0%     4   18.3  15.1   9.5  20.7   5.3
  7. tbr1-p013701.attga.ip.att.ne  0.0%     4   26.5  26.7  26.3  26.9   0.3
  8. tbr2-cl17.wswdc.ip.att.net    0.0%     4   36.3  31.3  29.3  36.3   3.3
  9. 12.123.8.109                  0.0%     4   24.0  25.5  24.0  26.8   1.1
 10. so6-3-0-2488M.ar1.DCA3.gblx.  0.0%     4   46.7  47.4  46.6  48.6   1.0
 11. pos1-0-0-155M.ar1.CLE1.gblx.  0.0%     4   67.4  49.9  42.8  67.4  11.7
 12. Testcom.s4-0-0-22-0.ar1.CLE1  0.0%     4   55.6  49.3  46.7  55.6   4.2
 13. ???                          100.0     4    0.0   0.0   0.0   0.0   0.0
fd0man at fd0man-laptop:~$

And another one:
fd0man at fd0man-laptop:~$ mtr -rc 4 www.test.com
HOST: fd0man-laptop               Loss%   Snt   Last   Avg  Best  Wrst StDev
  1. 192.168.0.1                   0.0%     4    0.8   0.9   0.8   0.9   0.0
  2. 73.62.36.1                    0.0%     4   10.5  10.9  10.2  11.9   0.8
  3. GE-1-1-ur01.D6decatur.ga.atl  0.0%     4   26.6  13.4   7.8  26.6   8.9
  4. 10g-9-1-ur01.D7decatur.ga.at  0.0%     4    9.2   9.6   8.8  11.1   1.0
  5. 10g-9-4-ar01.D1stonemtn.ga.a  0.0%     4   11.5  12.0   8.6  18.8   4.7
  6. 12.124.64.21                  0.0%     4   11.4  11.6  11.2  11.9   0.3
  7. tbr1-p013701.attga.ip.att.ne  0.0%     4   29.1  27.5  25.9  29.1   1.4
  8. tbr2-cl17.wswdc.ip.att.net    0.0%     4   32.0  29.0  27.3  32.0   2.1
  9. 12.123.8.109                  0.0%     4  187.2 125.2  25.9 244.4 107.4
 10. so6-3-0-2488M.ar1.DCA3.gblx.  0.0%     4   57.3  49.9  46.8  57.3   5.0
 11. pos1-0-0-155M.ar1.CLE1.gblx.  0.0%     4   56.1  46.6  42.5  56.1   6.3
 12. Testcom.s4-0-0-22-0.ar1.CLE1  0.0%     4   46.6  57.8  46.6  66.8   8.6
 13. ???                          100.0     4    0.0   0.0   0.0   0.0   0.0
fd0man at fd0man-laptop:~$

Unpredictable as to when, but both 10-g...decatur and 10-g...stonemtn are 
having issues, or intentionally dropping some ping packets, but I doubt the 
latter, since ComCast uses ping itself to diagnose the network.

	- Mike
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