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

Jared Mauch jared at puck.nether.net
Tue Sep 6 20:26:49 UTC 2005


On Tue, Sep 06, 2005 at 01:16:59PM -0400, andrew2 at one.net wrote:
> 
> owner-nanog at 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 at puck.nether.net
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.



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