Linux Journal: An Introduction to Using Linux as a Multipurpose FirewallFeb 25, 2000, 03:32 (4 Talkback[s])
(Other stories by Jeff Regan)
"High-speed Internet connections are becoming more readily available and popular for home computer users. ADSL (Asymmetric Digital Subscriber Line), Nortel's 1MB modem and cable modems all offer connection speeds many times faster than that of a standard 56K POTS (plain old telephone service) modem that most of us know all too well. The other big advantage of these new services is that they are always connected. That is, you don't need to dial your service provider with your modem to start up your Internet connection. When you turn on your computer, the connection is already there, and your operating system will establish a link as it boots up."
"Like the standard modem, these connections allow only one computer to connect to the Internet at a time. In some cases, additional IP addresses can be assigned to additional computers, but there is usually a monthly cost involved in providing this service."
"By installing Linux on that old 486 you have sitting in the corner collecting dust, you can create a firewall so all the computers on your local LAN can see the Internet, and at the same time, transfer data back and forth between each other... You don't even need a dedicated PC. A faster PC can simultaneously be used for other purposes while acting as the firewall; however, there are two main drawbacks with this approach: