nanog mailing list archives

Re: ICMP weirdness


From: Alon Tirosh <j0keralpha () gmail com>
Date: Mon, 18 Oct 2004 17:19:28 -0400


Comcast uses parts of 10/8 for cable modem addressing, and these are
pingable from within the comcast network. Could this be some other
internal equipment address as well?


On Mon, 18 Oct 2004 17:01:39 -0400, Jim Popovitch <jimpop () yahoo com> wrote:

On Mon, 2004-10-18 at 15:54, Stephen J. Wilcox wrote:
why not that seems ok to me.. ?

assuming you accept the 1918 assignment to your cable then its not unreasonable
that you can get to other end users on that network

Across other non-private IP space?  I am not all that familiar w/
RFC1918, but I would think that this goes against it, or should I assume
that Insight Broadband is part of Comcast?

-Jim P.


Steve



On Mon, 18 Oct 2004, Jim Popovitch wrote:


From Comcast Cable, at my home in Atlanta, I can ping 10.10.1.1....
which is pong'ed from a private client network hanging somewhere off of
Insight Broadband's network in the North Central part of the US.  Why on
god's green earth do network operators allow such nonsense as this?

-Jim P.

Traceroute -I 10.10.1.1 produces the following:

traceroute to 10.10.1.1 (10.10.1.1), 30 hops max, 38 byte packets
 1  10.238.10.1 (10.238.10.1)  29.089 ms  25.387 ms  28.574 ms
 2  66.56.22.66 (66.56.22.66)  30.923 ms  31.305 ms  33.142 ms
 3  66.56.22.70 (66.56.22.70)  35.945 ms  35.874 ms  36.832 ms
 4  c-66-56-23-38.atl.client2.attbi.com (66.56.23.38)  34.740 ms  35.041
ms  37.537 ms
 5  12.118.184.41 (12.118.184.41)  41.967 ms  45.584 ms  43.997 ms
 6  gbr2-p70.attga.ip.att.net (12.123.21.6)  44.988 ms  44.706 ms
43.033 ms
 7  tbr2-p013602.attga.ip.att.net (12.122.12.37)  49.353 ms  44.010 ms
45.244 ms
 8  12.122.10.138 (12.122.10.138)  62.244 ms  62.269 ms  62.148 ms
 9  gbr1-p40.sl9mo.ip.att.net (12.122.11.114)  60.922 ms  67.005 ms
60.264 ms
10  gar1-p360.sl9mo.ip.att.net (12.123.24.209)  59.572 ms  64.013 ms
60.198 ms
11  12-220-0-69.client.insightBB.com (12.220.0.69)  77.000 ms  76.050
ms  77.926 ms
12  12-220-7-198.client.insightBB.com (12.220.7.198)  95.437 ms  80.068
ms  84.076 ms
13  10.10.1.1 (10.10.1.1)  93.612 ms  97.280 ms  192.994 ms







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