When you look in your closet, do you see a pile of obsolete hardware that you just cannot bring yourself to throw out, despite the pleas of your family? If you want to share your home Internet connection and save a little money at the same time, dust off that old hardware and set up a Linux-based firewall. All you need is a 486 or better processor, two network adapters (only one if you're on dial-up), a switch or hub, diskette drive, and 12MB of RAM. In this article, we'll take a look at floppyfw and Coyote Linux, two free, open source projects that have shrunk Linux down to diskette size to implement a firewall.

Both floppyfw and Coyote Linux provide adequate protection for home or small office use. So which is right for you? Floppfw takes a minimalist approach that requires you to understand iptables in order to customize it. Its lack of remote administration could be seen as an advantage for both resource-constrained and security-conscious users. Running SSH or a Web server takes up memory and processor resources that could be used to support more users. It is also one less source of potential vulnerabilities. Those familiar with Linux and command-line administration will feel right at home with floppyfw.