[newbie] gateway/router help

[ajax]

I'm trying to set up a p200mmx 32mb ram as my gateway/router/firewall.  I'm having some problems. I'm using mdk8.1.  I have one network card connected to my cable modem and one to my hub.  The p200 can connect to the internet and can connect to my laptop.  My laptop can connect to the p200 but can't get to the internet (can't ping ip addresses nor urls).  I've tried to follow instructions on ip-tables but I seem to be missing something.  I've also tried using the connection sharing through the mandrake control center but it tells me that it can't set up DHCP server package.  I've checked and that is installed.  I get the internet ip through dhcp.  My internal ips are static.  Anyone have any ideas? Thanks