[84145] in North American Network Operators' Group
Re: level3.net in Chicago - high packet loss?!?
daemon@ATHENA.MIT.EDU (Jared Mauch)
Tue Sep 6 16:28:45 2005
Date: Tue, 6 Sep 2005 16:26:49 -0400
From: Jared Mauch <jared@puck.nether.net>
To: andrew2@one.net
Cc: nanog@merit.edu
In-Reply-To: <20050906171700.AA0DB183B@fiji.merit.edu>
Errors-To: owner-nanog@merit.edu
On Tue, Sep 06, 2005 at 01:16:59PM -0400, andrew2@one.net wrote:
>
> owner-nanog@merit.edu wrote:
>
> > Best Practices of wide-area diagnosis, anyone?
>
> I'd be interested in a discussion of this as well. To answer a slightly
> different question, I usually point the "ping and traceroute" geeks to
> Karl's wonderful treatise on the subject:
> http://www.iwl.com/Resources/Papers/icmp-echo_print.html.
i've found it useful to use a simple udp probe tool to test
networks in the past. You can test end-to-end loss and get something
reasonable.
The following expects you to know:
1) GCC/Makefiles
2) how to insure you link in your resolver and socket/nsl
functions
3) tweak your cpu compile options for your host.. but..
ftp://puck.nether.net/pub/jared/rtt-0.12.tar.gz
If your clocks are accurately synced, you can even get unidirectional
delay.
I usually run it like this:
./rtt -v <host>
you will need to run ./rtt_resp on the far end host.
You can also use iperf or similer tools to help customers
diagnose network problems, but a easy/lightweight daemon on a few
hosts is always fairly easy to play with in a quick-and-dirty way...
- jared
--
Jared Mauch | pgp key available via finger from jared@puck.nether.net
clue++; | http://puck.nether.net/~jared/ My statements are only mine.
