[84132] in North American Network Operators' Group
Re: level3.net in Chicago - high packet loss?!?
daemon@ATHENA.MIT.EDU (Jay R. Ashworth)
Tue Sep 6 12:54:01 2005
Date: Tue, 6 Sep 2005 12:53:34 -0400
From: "Jay R. Ashworth" <jra@baylink.com>
To: nanog@merit.edu
In-Reply-To: <20050906143912.GA49303@latency.net>; from Adam Rothschild <asr+nanog@latency.net> on Tue, Sep 06, 2005 at 10:39:12AM -0400
Errors-To: owner-nanog@merit.edu
On Tue, Sep 06, 2005 at 10:39:12AM -0400, Adam Rothschild wrote:
> On 2005-09-06-10:25:28, Network Fortius <netfortius@gmail.com> wrote:
> > And how exactly would you interpret the number returned by net_loss
> > (int), in a column called "LOSS", in reference to reachability of a
> > "hop" between two end points [...]
>
> I'd interpret it to mean you're hitting a control plane policer or
> somesuch, with no actual bearing on end-to-end performance, judging
> from the diagnostic output you've graciously provided us with.
>
> I find myself giving this lecture several times a week to random
> "gamer" customers upset that intermediary routers don't reply to their
> pings at full line rate; I'd expect slightly better critical thinking
> skills from the posters on this list, but I've been wrong before. :)
And yet, his client had a problem, with that link, and did not have a
problem with some other link, which, presumably, did *not* show that
indication.
Correlation does not imply causation, given, but it's certainly a
datapoint.
Best Practices of wide-area diagnosis, anyone?
Cheers,
-- jra
--
Jay R. Ashworth jra@baylink.com
Designer +-Internetworking------+----------+ RFC 2100
Ashworth & Associates | Best Practices Wiki | | '87 e24
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If you can read this... thank a system administrator. Or two. --me
