In case anyone is interested, I found a very good How-To on iptables:
IPTABLES - A Beginner's Tutorial
I need to work through it myself, as I'm no expert in iptables, but it looks thorough. I notice that he is an Ubuntu user, so the section at the end of the tutorial to add the initscript would be a little different for Gentoo/Sabayon Linux as the runlevel setup is different in Ubuntu and I have not yet worked out the equivalence.


