[4760] in North American Network Operators' Group
Re: ATM Traceroute middle packet loss?
daemon@ATHENA.MIT.EDU (Eric D. Madison)
Fri Sep 27 20:20:53 1996
Date: Fri, 27 Sep 1996 20:13:16 -0400
To: Sanjay Dani(maillists) <indus@professionals.com>, nanog@merit.edu
From: "Eric D. Madison" <madison@acsi.net>
No, it's not a Sun issue, it drops every other packet only if I got over
the ATM Backbone. I can trace to another router, a ATM Switch, A CSU
panel, anything and I get the same dropped packet.
I did further testing, and it is every other packet, not just the middle one.
Eric
At 05:11 PM 9/27/96 -0700, maillists wrote:
>
>> 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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