I love how you find some quarks here and there on the internet. It seems the public internet has some private addresses that are routable. It would appear that at or near AT&T is providing routes for 10.x.y.z addresses which is rather rediculous considering that 10.x.y.z is a private address and should not be routed on the internet at all. I would have thought that Comcast or AT&T would have dropped the packets before going through their entire network. Here is a trace from my location in New Jersey to 10.21.1.1.
Code
Tracing route to 10.21.1.1 over a maximum of 30 hops
1 1 ms 1 ms 1 ms c-68-37-228-30.hsd1.nj.comcast.net [68.37.228.30]
2 * * * Request timed out.
3 9 ms 9 ms 9 ms ge-2-1-ur01.union.nj.panjde.comcast.net [68.86.220.121]
4 9 ms 9 ms 9 ms po-10-ur02.union.nj.panjde.comcast.net [68.86.209.238]
5 12 ms 9 ms 9 ms po-10-ur01.jerseycity.nj.panjde.comcast.net [68.86.209.242]
6 12 ms 10 ms 9 ms po-10-ur02.jerseycity.nj.panjde.comcast.net [68.86.209.246]
7 9 ms 9 ms 9 ms po-10-ur01.narlington.nj.panjde.comcast.net [68.86.209.250]
8 8 ms 9 ms 9 ms 68.86.158.178
9 9 ms 9 ms 10 ms po-70-ar01.verona.nj.panjde.comcast.net [68.86.209.254]
10 18 ms 11 ms 11 ms po-10-ar01.plainfield.nj.panjde.comcast.net [68.86.208.5]
11 10 ms 12 ms 11 ms GE-2-0-cr01.plainfield.nj.core.comcast.net [68.86.211.2]
12 21 ms 11 ms 12 ms 12.118.102.17
13 34 ms 34 ms 36 ms tbr1.n54ny.ip.att.net [12.123.3.82]
14 38 ms 39 ms 37 ms tbr1.n54ny.ip.att.net [12.122.10.57]
15 37 ms 38 ms 38 ms cr1.cgcil.ip.att.net [12.122.1.190]
16 34 ms 35 ms 35 ms br2.cgcil.ip.att.net [12.127.0.194]
17 33 ms 33 ms 33 ms gar5.cgcil.ip.att.net [12.123.6.57]
18 41 ms 40 ms 40 ms 12-215-4-21.client.mchsi.com [12.215.4.21]
19 43 ms 44 ms 43 ms 10.21.1.1
Trace complete.
Think Comcast is nuts or something? You may be correct. Using my Linux webserver, hosted in Texas, I don't get any route to a 10.x.y.z address which is how it should be. Pretty crazy that stuff like this happens in some areas.
I'll also attach a trace to a different address from one of my Linux boxes. This is to 10.20.1.1.
Code
$ traceroute 10.20.1.1
traceroute to 10.20.1.1 (10.20.1.1), 30 hops max, 40 byte packets
1 c-68-37-228-30.hsd1.nj.comcast.net (68.37.228.30) 2.898 ms 1.583 ms 2.536 ms
2 * * *
3 ge-2-1-ur01.union.nj.panjde.comcast.net (68.86.220.121) 10.333 ms 9.515 ms 10.556 ms
4 po-10-ur02.union.nj.panjde.comcast.net (68.86.209.238) 8.683 ms 9.871 ms 9.939 ms
5 po-10-ur01.jerseycity.nj.panjde.comcast.net (68.86.209.242) 9.341 ms 11.745 ms 11.854 ms
6 po-10-ur02.jerseycity.nj.panjde.comcast.net (68.86.209.246) 11.234 ms 10.291 ms 12.064 ms
7 po-10-ur01.narlington.nj.panjde.comcast.net (68.86.209.250) 9.697 ms 10.676 ms 10.410 ms
8 68.86.158.178 (68.86.158.178) 10.873 ms 10.134 ms 10.508 ms
9 po-70-ar01.verona.nj.panjde.comcast.net (68.86.209.254) 11.353 ms 11.251 ms 13.187 ms
10 po-10-ar01.plainfield.nj.panjde.comcast.net (68.86.208.5) 11.430 ms 12.064 ms 12.871 ms
11 GE-2-0-cr01.plainfield.nj.core.comcast.net (68.86.211.2) 11.007 ms 12.025 ms 12.982 ms
12 12.118.102.17 (12.118.102.17) 11.518 ms 12.074 ms 13.048 ms
13 tbr1.n54ny.ip.att.net (12.123.3.82) 45.868 ms 46.182 ms 46.689 ms
14 tbr2.cgcil.ip.att.net (12.122.10.113) 47.581 ms 48.790 ms 50.476 ms
15 cr1.cgcil.ip.att.net (12.122.1.190) 47.889 ms 54.183 ms 50.529 ms
16 br2.cgcil.ip.att.net (12.127.0.194) 55.829 ms 45.072 ms 46.310 ms
17 gar2.mpsmn.ip.att.net (12.122.85.101) 45.889 ms 46.109 ms 45.205 ms
18 12-215-0-245.client.mchsi.com (12.215.0.245) 45.360 ms 44.831 ms 46.587 ms
19 12-215-15-130.client.mchsi.com (12.215.15.130) 48.963 ms 49.742 ms 52.061 ms
20 10.20.1.1 (10.20.1.1) 73.988 ms 58.125 ms 60.103 ms