network stress test tools

[Robert Donovan]

On Mon, 2004-09-13 at 12:29, Cory Petkovsek wrote:
> On Mon, Sep 13, 2004 at 08:09:20AM -0700, Gus Wirth wrote:
> > I need to stress test some network infrastructure which includes a portion
> > with a wireless bridge. I want to be able to evaluate packet loss, packet
> > corruption and throughput over a several day period. TCP/IP is the obvious
> > protocol but it may also have to support Novell IPX. I'm trying to make the
> > IPX requirement go away. Do some of you have a favorite tool you could
> > recommend for doing something like this? I'm off to search Google and
> > Freshmeat now but I would appreciate first-hand reports.
> > 
> > Gus
> 
> I know of no way to monitor the network as a whole for packet loss.  However
> testing from single points (including routers/bridges) will give you individual
> stats.  Use a utility that will copy files as you normally might.  Write a
> script to mount a network drive, copy files to a temp dir and remove them.
> Then have it repeat every 15 minutes or so.  Then on that node look at the
> network statistics:
> 
> # netstat -i|egrep eth2\|Iface
> Iface   MTU Met   RX-OK RX-ERR RX-DRP RX-OVR   TX-OK TX-ERR TX-DRP TX-OVR Flg
> eth2   1500   0 1105520      0      0      0 1799796      0      0      0 BMRU
> # iwconfig eth2|egrep "Rx |Tx "
>           Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
>           Tx excessive retries:0  Invalid misc:0   Missed beacon:0
> 
> Here is my wireless nic on my router.  Lots of Oks, no drops on this side.
> Next look at netstat -s for much more detailed information.  However this is
> per stack and not per interface.
> 
> You could use a utility like tcpblast, ping -f and friends, however even on a
> wired network they will provide packet loss because they test extreme
> throughput that no network will see in practical application.  You can also
> load the discard service (inetd) and use netcat or maybe tcpblast to dump a
> bunch of data to that port if you really want to do this kind of throughput
> testing, just expect packet loss (which is inherent anyway in networking which
> is why we have tcp).
> 
> Cory
> 
> -- 
> Cory Petkovsek                                       Adapting Information
> Adaptable IT Consulting                                Technology to Your
> (858) 705-1655                                                   Business
> cory at AdaptableIT.com                                  www.AdaptableIT.com

I'm replying to Cory's reply because I stupidly deleted Gus' original by
mistake. At the Dag repository
http://dag.wieers.com/home-made/apt/packages.php I found an app called
hammerhead, which is supposed to be for network stress testing. I
haven't used it, but it's the only thing I know of.

Robert Donovan