gShield (formerly Godot’s Modified Modular Firewall), is an aggressive, modular, ipchains-based firewall script. Features include: easy configuration through a BSD-style configuration file, optional IPmasq support, TCPwrapper-like funtionality for service access, and extremely restrictive defaults. It hopes to make administrating a comprehensive firewall easier, as well as offering robust protection.
You can download it from the following link: https://packetstormsecurity.com/files/download/10928/gShield-1.3.tgz
Source: https://packetstormsecurity.com/files/10928/gShield-1.3.tgz.html