Re: [Hampshire] network testing

James Courtier-Dutton <james.dutton@???>
wrote:
> Does anyone know of any Linux tools to test
> TCP/IP networks. If I have a redundant network,
> and I pull a cable, I wish to test the time it
> takes to automatically fail over and network
> traffic resumes.

I've just used ping - with a short interval - and
iperf to do similar testing.

> I wish to take these measurements on a per
> direction basis. I.e. traffic might resume in
> one direction before it resumes in another.

I wasn't trying to measure that, though. I was
looking at STP/RSTP reconvergence on a fibre ring,
using some fairly heavy iron - Cisco 6504 routers
- so I could gather any extra data from the
routers themselves.

In the past, I have rigged up a "one-way ping"
using netcat. That might work for you; you'd
probably want to have your test hosts' clocks NTP
sync'd.

> I suppose I am looking for a tool that can send
> sequenced UDP packets from a source to a
> destination, and the destination log which
> packets were received. I can then determine how
> long the network was down based on the amount of
> packets lost.

Sounds like netcat and a little shell script might
do that for you. Unfortunately, I don't have
copies of the scripts; that was job[-2].

Nick.

--
Nick Chalk ................. once a Radio Designer
Confidence is failing to understand the problem.