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Ben Hetland wrote:
> Can someone explain what's going on during the trace shown below? Why
> doesn't the trace stop when it reaches the target in step 6?
>
> The sample below was done using XP (behind a NAT'ed router), but similar
> behavior is observed with 'traceroute' on Linux.
>
>
> C:\Documents and Settings\benh>tracert cr1.ge1-1-0.osl255.netcom.no
>
> Tracing route to cr1.ge1-1-0.osl255.netcom.no [212.169.116.109]
> over a maximum of 30 hops:
>
> 1 <1 ms <1 ms <1 ms amilo2.storsandmo [192.168.2.95]
> 2 996 ms 957 ms 1017 ms 212.169.98.1
> 3 1283 ms 1023 ms 751 ms 10.240.239.5
> 4 758 ms 992 ms 441 ms 212.45.186.194
> 5 1078 ms 1222 ms 1222 ms 212.45.186.94
> 6 554 ms 803 ms 558 ms cr1.ge1-1-0.osl255.netcom.no
> [212.169.116.109]
> 7 1501 ms 920 ms 944 ms osl200-gw01.teliamobile.net [192.36.252.162]
> 8 * * * Request timed out.
> 9 * * * Request timed out.
> 10 * * * Request timed out.
> 11 * * * Request timed out.
> 12 * * * Request timed out.
> 13 * * * Request timed out.
> 14 ^C
> C:\Documents and Settings\benh>

My best guess is that somewhere between osl200-gw01.teliamobile.net and
the next hop, someone has implemented a filter to drop ICMP ECHO REPLY
packets. Thus, you only get ping replies (ICMP ECHO REPLY) from those
hops up to osl200..., and the ping replies from anywhere past that point
are not returned to you.

- --

Lew Pitcher, IT Specialist, Corporate Technology Solutions,
Enterprise Technology Solutions, TD Bank Financial Group

(Opinions expressed here are my own, not my employer's)
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