Traceroute Anomaly

Gregory Kuhn freebsd-net at lists.ctch.net
Fri Aug 20 11:06:20 PDT 2004


At 11:30 AM 8/20/2004, you wrote:

>In reply to Gregory Kuhn <freebsd-net at lists.ctch.net> :
>
> > Hello,
> >
> >
> >          I have discovered an anomaly (I am sure it was discovered long
> > ago) when trying to traceroute to my FBSD 4.8 and 4.9 servers.  Here are
> > the details.
>
>Have you set sysctl net.inet.udp.blackhole=1 ?
>
>If so, the FreeBSD box will drop the traceroute UDP probes and you'll
>never see the host itself in traceroute output.

Eli,


         Thank you.  That was it.  Changed net.inet.udp.blackhole=1 to 
net.inet.udp.blackhole=0 and traces work.  I'll remember to read the man 
pages more closely too next time.

Greg

>                 --eli
>
>
>




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