[52813] in North American Network Operators' Group
Re: question concerning traceroute?
daemon@ATHENA.MIT.EDU (Andy Johnson)
Thu Oct 17 11:02:44 2002
From: "Andy Johnson" <andyjohnson@ij.net>
To: "Darrell Carley" <darrell@national-net.com>
Cc: <nanog@merit.edu>
Date: Thu, 17 Oct 2002 11:00:46 -0400
Errors-To: owner-nanog-outgoing@merit.edu
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There used to be an old flag you could set on an ICMP_ECHO request to =
record the path the echo reply takes back (ping -R or -r?), but =
apparently its not used much anymore. Probably just as well.. it could =
only hold ~8 hops..
Andy
----- Original Message -----=20
From: Darrell Carley=20
To: nanog@merit.edu=20
Sent: Thursday, October 17, 2002 10:31 AM
Subject: question concerning traceroute?
I am trying to troubleshoot a latency issue for some of our networks, =
and was wondering about this.Knowing that routing isn't always =
symmetrical, is it possible for a traceroute to traverse a different =
reverse path, than the path that it took to get there? .or will it =
provide a trace of the path the packet took to reach the destination? =20
According to definition, is should take the same path, but are there =
any other cases that I should be aware of?
=20
Darrell
=20
=20
=20
=20
=20
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<DIV><FONT face=3DArial size=3D2>There used to be an old flag you could =
set on an=20
ICMP_ECHO request to record the path the echo reply takes back (ping -R =
or -r?),=20
but apparently its not used much anymore. Probably just as well.. it =
could only=20
hold ~8 hops..</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Andy</FONT></DIV>
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<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Ddarrell@national-net.com=20
href=3D"mailto:darrell@national-net.com">Darrell Carley</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A title=3Dnanog@merit.edu=20
href=3D"mailto:nanog@merit.edu">nanog@merit.edu</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Thursday, October 17, =
2002 10:31=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> question concerning=20
traceroute?</DIV>
<DIV><BR></DIV>
<DIV class=3DSection1>
<P class=3DMsoNormal><FONT face=3DArial size=3D2><SPAN=20
style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">I am trying to =
troubleshoot a=20
latency issue for some of our networks, and was wondering about =
this=85Knowing=20
that routing isn=92t always symmetrical, is it possible for a =
traceroute to=20
traverse a different reverse path, than the path that it took to get=20
there?<SPAN style=3D"mso-spacerun: yes"> </SPAN>=85or will it =
provide a=20
trace of the path the packet took to reach the destination?<SPAN=20
style=3D"mso-spacerun: yes"> =
</SPAN><o:p></o:p></SPAN></FONT></P>
<P class=3DMsoNormal><FONT face=3DArial size=3D2><SPAN=20
style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">According to definition, =
is should=20
take the same path, but are there any other cases that I should be =
aware=20
of?<o:p></o:p></SPAN></FONT></P>
<P class=3DMsoNormal><FONT face=3DArial size=3D2><SPAN=20
style=3D"FONT-SIZE: 10pt; FONT-FAMILY: =
Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=3DMsoNormal><FONT face=3DArial size=3D2><SPAN=20
style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial; mso-no-proof: =
yes">Darrell</SPAN></FONT><SPAN=20
style=3D"mso-no-proof: yes"><o:p></o:p></SPAN></P>
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yes"> <o:p></o:p></SPAN></FONT></P>
<P class=3DMsoNormal><FONT face=3D"Times New Roman" size=3D3><SPAN=20
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