[167655] in North American Network Operators' Group
RE: Help me make sense of these traceroutes please
daemon@ATHENA.MIT.EDU (Josephson, Marcus)
Thu Dec 26 11:22:06 2013
From: "Josephson, Marcus" <Marcus.Josephson@Level3.com>
To: "nanog@nanog.org" <nanog@nanog.org>
Date: Thu, 26 Dec 2013 16:21:45 +0000
In-Reply-To: <CAAAwwbUY685zRVA3RBnRFqfdz45pGqqQ64T3PmiUJO6J1KXCpw@mail.gmail.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Start at slide 50:
This is documented further by the following Nanog presentation. http://www.=
nanog.org/meetings/nanog47/presentations/Sunday/RAS_Traceroute_N47_Sun.pdf
-Marcus
-----Original Message-----
From: Jimmy Hess [mailto:mysidia@gmail.com]=20
Sent: Wednesday, December 25, 2013 10:28 AM
To: Martin Hotze
Cc: nanog@nanog.org
Subject: Re: Help me make sense of these traceroutes please
On Wed, Dec 25, 2013 at 8:03 AM, Martin Hotze <m.hotze@hotze.com> wrote:
>
> > On 2013-12-25 00:16, Sam Moats wrote:
>
...
> > You are likely seeing the effects of asymmetric routing.
> . .. or the effect of passing traffic through NSA infrastructure.
>
>
Ah... NSA. That's probably it.
So much for my theory of a Router virtual chassis straddling the atlantic=
.
or the extra kinetic energy carried by the overseas-bound packet took long=
er for the router to absorb and rebound with an ICMP.
But in all seriousness --- what is probably happening here, is the result =
of extra "hops" that don't show up in traceroute.
MPLS tunnels could well fit the bill.
Other things to consider when latency seems sensitive to destination IP ---=
are preceding device in the traceroute might also have multiple links to t=
he same device; with one link congested and some form of IP-based load sha=
ring, that happens to be the toward-overseas link.
> SCNR, #m
--
-JH
