So you need the outside world to have access to some box’s on your internal network. first you should use Static DHCPto tell static the IP’s of the computer you’re routing to. Then you of course need to know the inbound from the outside world and the port on the computer you are forwarding too. For this example we’ll forward WAN (Wide Area Network (or (probably) the Internet)) port 8080 to a local dev box running Apache on httpd (we assume you know how to set apache up and make sure it’s working on the LAN(Local Area Network)).

NOTE: this assumes that you’ve read my previous post on basic iptables setup on the desktopSo I just spent the longest time trying to determine what ports I needed to browse and use samba shares. The sad answer is it’s just one.iptables -A INPUT -p udp –sport 137 -j ACCEPTthe catch with all the information I found with google was that most of it was for samba servers. I didn’t want that.

The Best guide for learning the basics of iptables is here Linux 2.4 Stateful firewall design for the most part it continues to apply to the 2.6 kernel. The only things that won’t apply to your linux system will be: emerge if you aren’t on gentoo, and the kernel options which have changed since 2.4 and even a couple of times during 2.6. I’m not going to cover those here. If you need help building your kernel or installing iptables I suggest that you consult with either the iptables home page or even better your distribution.