i have a machine with a static ip that i'd like to set up as a
firewall/gateway.  the machine is a dell optiplex gx150 with 2 3com
3c905x nic cards, running freebsd4.6-RELEASE-p1.  the firewall/nat
software i'd like to use is either ipfw/natd or ipfilter/ipnat.  i'd
like to be able to provide a basic set of firewall
rules/filtering/firewall loggin/network address translation for 5-10
other machines, windows 2000 and freebsd, all with static addresses,
hooked up to this machine through a hublet. i've been trying to
research how to do this on my own for the past week and a half,
failing miserably, using online help docs and the freebsd unleashed
book.  so far i haven't been able to get it going, after a week and a
half of recompiling, reinstalling, reconfiguring, reading docs.  i
have other projects to work on and don't have a lot more time to spend
on this, but would like to ask for the assistance of a guru in this
field for help on setting this up.

thanks.

Greetings!

Have you tried this:

FreeBSD Firewall Configuration:
http://www.acme.com/firewall.html

What problems are you facing exactly?  Try running through the
step-by-step in the natd manpage; type "man natd" for this.  Let me
know which steps you're having problems with.

Another common mistake is people forgetting to put
gateway_enable="YES" in /etc/rc.conf.  If you have that, try "sysctl
net.inet.ip.forwarding=1" to manually enable it.

the problems vary depending on the literature i'm following.

most common problem is, once it's set up, i have ethernet cable going
from the wall to cl0, then ethernet from xl1 to a hub, then i plug in
a 2nd box to the hublet and change it's default gateway to the ip of
xl0 on the gateway box, i get no network connection going either way. 
the boxes i'm going to set up behind the gateway all have static ip's
and are mostly webservers.  and this usually happens when i have the
firewall set to 'open' in /etc/rc.conf, so i should at least be able
ping other machines from behind the firewall... (i think)

other problems:  some literature i follow has the machine locked down
so tight i can't even boot it up!

i will try http://www.acme.com/firewall.html probably tuesday and will
let you know what happens... (like i said, i wish i had more time to
spend on this, but i already gave it more than a week and there are
other things i need to do for work that are more pressing, but i'd
still like to get this project going)

and thanks for responding...

If you are looking to install a firewall only, I suggest that you try
installing <a href="http://www.OpenBSD.org/">OpenBSD</a>.  I do
exactly what you need to do at home and at school, and I have never
had any problems.  <a
href="http://www.openbsd.org/faq/faq6.html#PF">This section</a> in the
OpenBSD <a href="http://www.openbsd.org/faq/">FAQ</a> should contain
exactly what you need to set up your firewall/NAT.

There is also no need do any recompiling of any sort, and
configuration is as easy as editing two lines to enable firewalling
and NATing.

For more examples of setting up a firewall using OpenBSD, check out <a
href="http://www.deadly.org/pf-howto/">The OpenBSD Packet Filter
HOWTO</a>.

I also suggest that you try setting up stuff with only two computers
first, instead of taking all your computers down from the net.