Latency generator?

Wed Jun 25 17:01:27 UTC 2003

On Wed, Jun 25, 2003 at 12:48:29PM -0400, Temkin, David quacked:
> Does anyone know of any free, cheap, or potentially rentable latency
> generators?  Ideally I'd like something that just sits between two ethernet
> devices to induce layer 2/3 latency in traffic, but am open to any
> options...

Dummynet.  We use it at Emulab (http://www.emulab.net/) to do
exactly what you're describing.  You have to use it in conjunction
with the bridging code, and then you can just do it.  By default,
it still uses the ipfw firewall rules to match traffic, so it only
delays IP, but that could probably be fixed with a little hacking
if you also want to delay ARP and other things.

Built into FreeBSD.  Should work mostly out of the box.
It'll also do traffic shaping and whatnot.

Your .signature disclaimer was longer than your message, by the way. ;-)

  -Dave

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