[PLUG] Odd ping response behavior from private IP addresses

[Matt Alexander]

On Fri, 2 Aug 2002, J Henshaw wrote:

> A traceroute would help clarify things.

Hmm...  looks like it's bouncing between two systems until the 30 hop
limit is reached.


traceroute to 172.16.1.5 (172.16.1.5), 30 hops max, 38 byte packets
1  10.32.128.1 (10.32.128.1)  18.855 ms  12.777 ms  12.239 ms
2  ip68-2-1-5.ph.ph.cox.net (68.2.1.5)  30.117 ms  11.570 ms  11.076 ms
3  chnddsrc01-gew0303.rd.ph.cox.net (68.2.14.5)  35.806 ms  33.819 ms 17.413 ms
4  ip68-2-1-5.ph.ph.cox.net (68.2.1.5)  144.879 ms  14.416 ms  40.034 ms
5  chnddsrc01-gew0303.rd.ph.cox.net (68.2.14.5)  13.868 ms  55.412 ms 17.750 ms
6  ip68-2-1-5.ph.ph.cox.net (68.2.1.5)  18.584 ms  15.195 ms  15.042 ms
7  chnddsrc01-gew0303.rd.ph.cox.net (68.2.14.5)  39.512 ms  19.261 ms  11.061 ms
8  ip68-2-1-5.ph.ph.cox.net (68.2.1.5)  36.169 ms  19.474 ms 84.519 ms
9  chnddsrc01-gew0303.rd.ph.cox.net (68.2.14.5)  26.928 ms 26.657 ms  29.603 ms
10  ip68-2-1-5.ph.ph.cox.net (68.2.1.5)  13.232 ms  25.648 ms 45.739 ms
etc...


traceroute to 172.16.1.6 (172.16.1.6), 30 hops max, 38 byte packets
1  10.32.128.1 (10.32.128.1)  13.288 ms  26.473 ms  24.076 ms
2  ip68-2-1-5.ph.ph.cox.net (68.2.1.5)  167.170 ms  48.484 ms  84.706 ms
3  chnddsrc01-gew0303.rd.ph.cox.net (68.2.14.5)  49.574 ms  58.097 ms 27.378 ms
4  ip68-2-0-2.ph.ph.cox.net (68.2.0.2)  94.635 ms  29.016 ms  49.975 ms
5  chnddsrc01-gew0304.rd.ph.cox.net (68.2.14.9)  13.953 ms  84.942 ms 58.122 ms
6  ip68-2-0-2.ph.ph.cox.net (68.2.0.2)  13.596 ms  93.175 ms  16.689 ms
7  chnddsrc01-gew0304.rd.ph.cox.net (68.2.14.9)  11.721 ms  146.168 ms  86.775 ms
8  ip68-2-0-2.ph.ph.cox.net (68.2.0.2)  21.260 ms  22.275 ms 20.621 ms
9  chnddsrc01-gew0304.rd.ph.cox.net (68.2.14.9)  16.112 ms 60.123 ms  53.734 ms
10  ip68-2-0-2.ph.ph.cox.net (68.2.0.2)  27.901 ms  16.402 ms 15.778 ms
etc...

OK, so that explains the "Time to live exceeded" message from ping, but
how would these systems have to be configured in order to produce these
results?
~M