iptables and NAT [Solved]

[ppeetteerr]

I'm trying to turn my computer into a router and I'm having some trouble with iptables and NAT. I'm following this guide here
[url] http://www.gentoo.org/doc/en/home-router-howto.xml[/url]

When I go to setup my kernel I need to enable Full NAT but the option isn't available in menuconfig. When I switch to xconfig it is grayed out meaning that it depends on something that isn't enabled. So what enables FULL NAT?

Peter

PS. I wasn't sure weather this belonged here or in kernel config. I put it here

PSS It was connection tracking. I thought it was allready enabled