Copyright © 2004 Sulyok Péter
This tutorial is written for users who do not know about firewalls and IP packet filtering in the Linux kernel. It tells you how to configure your firewall on your Fedora Core system for using it as an Internet gateway for your local network, and for sharing Internet connection.
In this tutorial, the sample configuration is the following: /dev/eth0 is the device connected to the local network, and /dev/eth1 is the device connected to the Internet (via a cable modem for example). We would like:
all computers in the local network to be able to access the Internet,
to accept incoming connections from the Internet only if that is our intention,
to forward certain incoming connections—from the Internet—to certain computers in the local network.