Firewalling a single machine

[bsamuels@datamansys.co.uk]

I'm running Potato with a 2.2.14 kernel.

Is it possible to use Ipchains to firewall a single machine?

The various documents on Ipchains which I have read (and can't understand
anyway) seem to assume that the firewall will be on its own machine and talks
in terms of two network cards.

I have a small network (3 machines) at home and I have a modem in one machine
which is the only machine that will access the internet.  The other machines will
not be accessing the internet in any way.

Can I setup Ipchains on the single machine to act as a firewall.  I think that
what I need is a packet filter.

As far as firewalls/Ipchains goes I am a complete idiot beginner ( I can produce
certificates ) so _please_ keep the hints simple.

I have tried Mason and that seems to create rules that incorporate my IP address
which may change each time I log on via my ISP. So I can't see how that will
work.

I have compiled the various appropriate options into the kernel.  I could, at
least, understand that much.

I want to make my machine secure from outside interference when I'm on the
internet.

Barry Samuels