Ossar,
as I understand you right, you want to forward some connections to a internal server like to forward everthing arriving on port 80 at your router to an internal webserver ?!? The settings you posted are responsible for the router itself, if it forwards broadcasts and pings ... . To do NAT, you have to install iptables (
www.netfilter.og). This allows you to NAT and forward connections. You also have to compile your kernel with this settings.
Would be helpful to give us more information what you want o forward/NAT (ports, connections ..)!
Cheers
bagira