[109659] in North American Network Operators' Group
Re: Recommendation of Tools
daemon@ATHENA.MIT.EDU (Nick Hilliard)
Wed Dec 3 17:54:43 2008
X-Envelope-To: nanog@nanog.org
Date: Wed, 03 Dec 2008 22:54:08 +0000
From: Nick Hilliard <nick@foobar.org>
To: "Lee, Steven (NSG Malaysia)" <kin-wei.lee@hp.com>
In-Reply-To: <084962C061414240A0CDB4BE328A9B2D0BB10BAED8@GVW1100EXC.americas.hpqcorp.net>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
Lee, Steven (NSG Malaysia) wrote:
> Hi all, do you have any recommended tools that can measure latency/delay
> hop by hop basis? Preferable the tools can measure the running (live)
> traffic.
Tools like smokeping, mtr, traceroute and all that will give you highly
skewed results, whose accuracy will usually depend entirely on how busy the
CPU is which responds to host IP packets (whether icmp, udp or even tcp).
As most large routers push everything through hardware, if you measure your
hop latency using inline router response times, your results will be trash.
If you want to do this properly, you will need to install dedicated
measurement hosts hanging off each router and measure response times to
them instead. RIPE TTM boxes are pretty good for this:
http://www.ripe.net/ttm/
Nick
