FreeBSD and DUMMYNET? On Wed, 25 Jun 2003, Temkin, David wrote: :>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... :> :> :> :>David Temkin :>S-I-G :>401 City Avenue :>Bala Cynwyd, PA 19004 :>http://www.sig.com <http://www.sig.com> :> :> :> :>IMPORTANT:The information contained in this email and/or its attachments is :>confidential. If you are not the intended recipient, please notify the :>sender immediately by reply and immediately delete this message and all its :>attachments. Any review, use, reproduction, disclosure or dissemination of :>this message or any attachment by an unintended recipient is strictly :>prohibited. Neither this message nor any attachment is intended as or :>should be construed as an offer, solicitation or recommendation to buy or :>sell any security or other financial instrument. Neither the sender, his or :>her employer nor any of their respective affiliates makes any warranties as :>to the completeness or accuracy of any of the information contained herein :>or that this message or any of its attachments is free of viruses. :> :> :>

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 -- work: dga@lcs.mit.edu me: dga@pobox.com MIT Laboratory for Computer Science http://www.angio.net/ I do not accept unsolicited commercial email. Do not spam me.