Traceroute Anomaly

Barney Wolff barney at
Fri Aug 20 10:23:17 PDT 2004

On Fri, Aug 20, 2004 at 11:01:31AM -0600, Gregory Kuhn wrote:
>         My question is this;
> Why can I do a traceroute using the DOS version of traceroute (tracert) to 
> any of my FreeBSD boxes, but I am not able to do so from another FreeBSD 
> box?  Furthermore, it is not just from my own boxes that I am unable to do 
> a traceroute.  Using the traceroutes listed at I again 
> am unable to trace back to my FBSD boxes.

If I remember correctly, MS's tracert sends ICMP packets, while traditionally
Unix traceroutes send UDP.  You're blocking the UDP somewhere, presumably.
tcpdump and/or adding logging to your firewall rules should tell you more.

Barney Wolff
I'm available by contract or FT, in the NYC metro area or via the 'Net.

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