From: "sai" <sonicsai at gmail dot com>

> [2] An IDS should be connected to lots of different places on your
> network and needs to have a massive CPU and hard disk.
> A firewall needs a low end cpu and no hard disk. It is connected to one 
> place.
> Totally different machines. Totally different purpose.

I also would say they have very different approaches.  A good IDS system is 
a sneaky thing that watches for intruders.  A firewall is a bold thing that 
blocks them.  However, I can see the virtue of having some easier hooks 
built into m0n0wall for other IDS systems.

                        Lee