nanog mailing list archives

Re: level3.net in Chicago - high packet loss?!?


From: "Jay R. Ashworth" <jra () baylink com>
Date: Tue, 6 Sep 2005 12:53:34 -0400


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
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      If you can read this... thank a system administrator.  Or two.  --me


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