Sounds like you really want a proxy. You may still want to set up nat
as well, for chat and news, or maybe not. I've been used wwwwoffled
for a few months now. It's currently running on my 840AV, running
netbsd. It proxies for all the browsers and ftp on its own host, and
also for Netscape for MacOS running on the Q630. I set all the disk
cache sizes to zero (letting the proxy do its job); now Netscape 3.05
under MacOS 8.1 never crashes! The big advantage for me is that I can
view pages under different browsers without going out over the modem
each time.

wwwoffle is in the package system. It's very easy to use. It serves a
"control" page to the localhost or to the clients it proxies for,
(password optional) from which you can edit the configuration file or
check the cache (to see what the little monsters are up to). You could
start with the defaults, and then block sites or otherwise tweak away
as needed. wwwoffle can be set to go out to a proxy itself, which you
would need for the cable modem connection.

What's gopher? :) Seriously, unless your school is running a gopher
server, you can probably skip that, or leave it to be picked up by the
nat.

The limiting factor for the nat and proxy setups I've experimented
with is the modem. With your cable modem, you could probably handle
quite a few clients. 

On Sat, 13 Mar 1999, Michael G. Schabert wrote:

> Hi guys,
> I have a (hopefully) quickie question regarding IP-NAT. Is it possible to
> make the other machines authenticate before allowing them to use the 'Net?
> I ask because I'd prefer to drop my employer's WinNT server (IIS) which is
> currently set up with the web proxy, so that when you wish to access a
> remote site, it'll pop up an authentication box for username/passwd. The
> district logs the users & the sites they visit, but I'm not as concerned
> with that as I am with just not allowing unauthorized users to access the
> 'Net (elementary school). So, would I have to actually run a proxy, or can
> I do it with some funky incantation over IP-NAT? If a proxy, what's
> available, & what's good? One final...about how many machines could I
> expect a Q700 to be able to do NAT for at once (on a cable "modem"
> connection)? I just hate the crap with the proxy where I would have to
> manually set up any services other than web, gopher, ftp. Since we're
> primarily Mac, my options are limited to the socks proxy in addition to the
> web proxy, whereas if we were WinTel, the WinSock proxy would be
> nice-n-easy.