transparent firewall box

[Allen Ahoffman <ahoffman@announce.com>]

Hi:
Can someone recommend the following configs:
I want a box that is basically transparent to the internal clients.
e.g.
                 router
                    firewall
          box1 box2 box3 box4
so box1 2 3 and 4 use the router's ip(s) as gateway
and not the firewall's internal ethernet.
and the router doens' knwo the difference.
But I can fireall each internal ip with separate rules.
e.g. dmz for some, ...
it would be nice to have straightforward rules like:
internal IP 208.242.184.9
	port { 80; 22; 143; ...; };
		accept from all except 195.284.44.33; };
	else deny;
...
Something nice like this with straightforward syntax.
any suggestions?
And,
Anyone seen simple firwall system which allows eth0: eth0:1 eth0:2
to each have their own rules, to perform different restrictions on a
single NIC system.