Subject: Re: Simulation app?
To: Peter Eisch <firstname.lastname@example.org>
From: Chuck Swiger <email@example.com>
Date: 05/22/2007 12:21:32
On May 22, 2007, at 11:56 AM, Peter Eisch wrote:
> Is there a tool native or pkgsrc that can be used to introduce
> network delay
> based on the source or destination address? I could see altq being
> used to
> throttle usage, but I'd like to simulate both terrestrial and
> connections between interfaces on my netbsd router.
> I'd imagine this being a userland program that uses a tap interface
> on each
> side of the router that includes a config with src, dst, delay triads.
> Any pointers someone can afford to spare?
ALTQ or IPFW+dummynet are the two common approaches to introducing
network bandwidth management or adding latency, and you should be
able to configure rulesets to match specific src or dst netblocks as
needed. It would not be impossible to write a userland tool to do
something similar, perhaps using divert sockets the way the userland
natd program works, or perhaps to use a proxy (either explicit or
transparent proxy) approach instead.
PS: However, it's not clear whether NetBSD has imported IPFW+dummynet
from FreeBSD; if not, then using FreeBSD as your platform might be
better for this sort of testing....