Linux.com: Linux and Windows NT 4.0: Part VII, RoutingNov 23, 2000, 20:03 (0 Talkback[s])
(Other stories by Chris Campbell)
"Whether for Internet connectivity or wide area networking to various physical locations, routing has become an invaluable asset to networking. Although routers have existed since the original ARPAnet, they have become increasing more common in corporate environments as the 1990's trend of local area networking grew into Wide and Metropolitan area networks."
"The first step in both Windows NT and Linux is to add a second network interface card. One card must be connected to the local area network, the second being routed to the network that the LAN will use. The local NIC must have a local IP address and be functioning. The external NIC must also function, obviously, but it must have an IP address in the external range."
"Like almost any essential task in Linux, there are many ways to set-up routing. Here we will briefly cover just one such way. For the benefit of readers with older distributions, we will cover routing procedures that function in both newer and older Linux's. Again, for more advanced tasks, be sure to read the how-to's."