[4759] in North American Network Operators' Group
Re: ATM Traceroute middle packet loss?
daemon@ATHENA.MIT.EDU (Sanjay Dani(maillists))
Fri Sep 27 20:16:39 1996
Date: Fri, 27 Sep 1996 17:11:35 -0700 (PDT)
From: Sanjay Dani(maillists) <indus@professionals.com>
To: nanog@merit.edu, madison@acsi.net
> hmm..
> Seems that every traceroute across an ATM link will result in the middle
> packet being dropped. The ATM Switch nor the Router have any idea that it
> is the second packet.. weird! Anyone have a clue to why that is?
>
> Tracing the route to ns2
> 1 206.222.97.6 44msec 44msec 44msec
> 2 ns2.acsi.net (206.222.97.50) 44 msec * 44 msec
I don't think it has got anything to do with ATM. I
bet you that ns2.acsi.net is a Solaris 2 box. Solaris
drops every other icmp echo if it comes too close to
the last one. This I was told is an inadvertent bug
although Sun could claim it to be a feature against
an ICMP flood attack ;-)
Try tracerouting to sun.com (a SunOS box) and
playground.sun.com (Solaris 2). You'll see the difference.
Also try traceroute with the -q parameter greater than
the default of 3 packets each destination.
Sanjay.
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