comcast routing problems

[Ben Scott]

On Sun, Nov 1, 2009 at 8:03 AM, Frank DiPrete <fdiprete at comcast.net> wrote:
> My router is returning max hops exceeded.

  *Your* router is returning that?  If so, something's wrong on your
router.  TTL (Time To Live) is a counter.  Every router hop, it gets
decreased by one.  If it hits zero, that router sends a ICMP "Time
Exceeded" message to the sender (you).

  The initial TTL is usually something like 64 or 128.  If *your*
router is returning the Time Exceeded message, then TTL reached zero
within your router.  That suggests a routing loop within your network,
eating up TTL until it expires.

> I'm trying to figure out if it is a comcast problem, a qwest problem,
> or a specific comcast problem after my super terrific speed upgrade.

  One of the first things you want to do is run a traceroute to the
problem destination.  That will help give you an idea of what you can
reach, and what you cannot.

> Any lucky people out there able to get to them?

  I opened the web site in my browser with no problem.  I'm in Dover,
NH, on Comcast "home".  Here's my traceroute:

$ traceroute www.linuxquestions.org
traceroute to www.linuxquestions.org (75.126.162.205), 30 hops max, 40
byte packets
 1  noid (10.10.10.1)  0.652 ms  1.572 ms  1.896 ms
 2  73.194.244.1 (73.194.244.1)  9.164 ms  15.437 ms  20.242 ms
 3  ge-1-2-ur01.dover.nh.boston.comcast.net (68.87.153.1)  21.782 ms
22.290 ms  22.711 ms
 4  te-5-3-ur01.exeter.nh.boston.comcast.net (68.87.145.93)  21.179 ms
 21.473 ms  21.572 ms
 5  po-21-ur02.manchester.nh.boston.comcast.net (68.87.145.110)
23.165 ms  23.268 ms  23.644 ms
 6  po-20-ur01.manchester.nh.boston.comcast.net (68.87.145.113)
22.715 ms  17.935 ms  18.142 ms
 7  po-23-ur01.nashua.nh.boston.comcast.net (68.87.145.117)  18.533 ms
 14.568 ms  14.257 ms
 8  po-20-ur02.nashua.nh.boston.comcast.net (68.87.147.158)  12.604 ms
 16.601 ms  16.529 ms
 9  be-23-ar01.needham.ma.boston.comcast.net (68.87.145.245)  17.938
ms  16.131 ms  11.333 ms
10  pos-0-1-0-0-ar01.chartford.ct.hartford.comcast.net (68.85.162.74)
19.468 ms  23.656 ms  23.889 ms
11  pos-2-5-0-0-cr01.newyork.ny.ibone.comcast.net (68.86.90.65)
26.824 ms  27.093 ms  27.195 ms
12  pos-1-14-0-0-cr01.mclean.va.ibone.comcast.net (68.86.85.93)
32.442 ms  32.708 ms  32.802 ms
13  pos-1-10-0-0-cr01.atlanta.ga.ibone.comcast.net (68.86.86.126)
54.132 ms  54.401 ms  54.498 ms
14  pos-1-10-0-0-cr01.dallas.tx.ibone.comcast.net (68.86.86.129)
75.541 ms  75.775 ms  79.325 ms
15  softlayer-cr01.dallas.tx.ibone.comcast.net (75.149.228.34)  76.229
ms  71.623 ms  73.463 ms
16  po2.dar02.dal01.dallas-datacenter.com (66.228.118.207)  77.679 ms
76.604 ms  76.666 ms
17  po2.fcr02.dal01.dallas-datacenter.com (66.228.118.182)  76.088 ms
73.631 ms  79.129 ms
18  www.linuxquestions.org (75.126.162.205)  78.850 ms  71.065 ms  74.596 ms
$

  For comparison, here's the traceroute from a "Comcast Workplace"
feed in Amesbury, MA:

arcgate$ traceroute www.linuxquestions.org
traceroute to www.linuxquestions.org (75.126.162.205), 30 hops max, 40
byte packets
 1  73.168.168.1 (73.168.168.1)  6.075 ms  11.455 ms  11.467 ms
 2  68.85.186.81 (68.85.186.81)  11.546 ms  11.532 ms  11.592 ms
 3  te-9-1-ur01.kingston.nh.boston.comcast.net (68.87.146.181)  11.613
ms  11.646 ms  11.665 ms
 4  te-8-1-ur02.londonderry.nh.boston.comcast.net (68.87.146.177)
12.051 ms  12.110 ms  12.137 ms
 5  te-9-1-ur01.londonderry.nh.boston.comcast.net (68.87.146.169)
11.664 ms  16.081 ms  16.150 ms
 6  te-0-9-0-4-ar01.needham.ma.boston.comcast.net (68.87.146.194)
16.212 ms  13.956 ms  13.290 ms
 7  pos-0-1-0-0-ar01.chartford.ct.hartford.comcast.net (68.85.162.74)
16.065 ms  15.157 ms  15.204 ms
 8  pos-2-3-0-0-cr01.newyork.ny.ibone.comcast.net (68.86.90.57)
18.076 ms  18.395 ms  22.310 ms
 9  pos-1-12-0-0-cr01.mclean.va.ibone.comcast.net (68.86.85.29)
28.228 ms  28.249 ms  28.273 ms
10  pos-1-15-0-0-cr01.atlanta.ga.ibone.comcast.net (68.86.85.69)
54.302 ms  54.330 ms  55.442 ms
11  pos-1-11-0-0-cr01.dallas.tx.ibone.comcast.net (68.86.85.221)
76.730 ms  77.890 ms  74.356 ms
12  softlayer-cr01.dallas.tx.ibone.comcast.net (75.149.228.34)  73.023
ms  74.074 ms  74.011 ms
13  po2.dar02.dal01.dallas-datacenter.com (66.228.118.207)  73.878 ms
74.590 ms  74.489 ms
14  po2.fcr02.dal01.dallas-datacenter.com (66.228.118.182)  74.626 ms
97.208 ms  97.056 ms
15  www.linuxquestions.org (75.126.162.205)  72.118 ms  74.035 ms  74.038 ms
arcgate$

-- Ben