[188195] in North American Network Operators' Group
RE: Figuring out traceroute
daemon@ATHENA.MIT.EDU (=?iso-8859-1?Q?J=FCrgen_Jaritsch?=)
Fri Mar 11 01:07:35 2016
X-Original-To: nanog@nanog.org
From: =?iso-8859-1?Q?J=FCrgen_Jaritsch?= <JJaritsch@anexia-it.com>
To: "nanog@nanog.org" <nanog@nanog.org>, "motamedi@cs.uoregon.edu"
<motamedi@cs.uoregon.edu>
Date: Fri, 11 Mar 2016 06:07:28 +0000
In-Reply-To: <CACGuEhH0h=47T266SBc0oX7xUvWQsddZDXO2g76r=Z1K1H+dfA@mail.gmail.com>
Errors-To: nanog-bounces@nanog.org
Looks like the device is always las-b3 (Los Angeles, border 3). As far as I=
know Telia works with IS-IS and multiple load balanced links from each bb =
(backbone) router to each border router. Usually they don't deal with L2 in=
case of customer BGP downlinks.
J=FCrgen Jaritsch
Head of Network & Infrastructure
ANEXIA Internetdienstleistungs GmbH
Telefon: +43-5-0556-300
Telefax: +43-5-0556-500
E-Mail: jj@anexia.at
Web: http://www.anexia.at
Anschrift Hauptsitz Klagenfurt: Feldkirchnerstra=DFe 140, 9020 Klagenfurt
Gesch=E4ftsf=FChrer: Alexander Windbichler
Firmenbuch: FN 289918a | Gerichtsstand: Klagenfurt | UID-Nummer: AT U632166=
01
-----Original Message-----
From: Reza Motamedi [motamedi@cs.uoregon.edu]
Received: Freitag, 11 M=E4rz 2016, 1:26
To: nanog@nanog.org [nanog@nanog.org]
Subject: Figuring out traceroute
Hi guys,
This might seem a bit of a trivial question, but I guess there is no harm
in asking. I am looking at a collection of traceroutes all go through the
following consecutive hops (* >> 213.248.98.238), as shown here (I kept the
DNSname just for completeness):
+ From >> To
+ (213.155.130.125:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.130.127:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.131.75:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.131.83:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.131.85:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.134.251:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.134.253:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.134.77:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.137.57:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (213.155.137.59:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.114.111:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.168:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.170:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.174:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.176:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.178:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.180:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.182:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.184:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.186:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.188:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.116.190:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.140.253:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
+ (62.115.140.255:las-b3-link.telia.net) >> (213.248.98.238:b
harti-ic-140621-las-b3.c.telia.net)
Given the way traceroute works (most of the times), which reports back the
ingress port of the router it hits, do you think it fair to assume that all
the hops that I see on the `From` hop are all different ports of one
router? I think the other explanation is that there is switch (or something
that does not have IP footprint) between `From` side and `To` side. How
probable do you think this second explanation is?
Best Regards
Reza Motamedi (R.M)
