[ Thanks to Kevin
Reichard for this link. ]
“Linux can route network traffic from one network segment to
another. Routing is normally done on a PC with two or more network
adapters. This article presents a configuration using a pair of
Ethernet adapters. More specifically, the article examines how a
Linux computer can link a local network to the Internet through an
Ethernet-attached device like a cable modem or a DSL modem. The
article examines the basic concepts pertaining to routing, network
address translation (NAT), firewalls, and a program called
ipchains.”
“Individual sections address each concept. The last section
combines the basics into a sample configuration for linking a local
network to the Internet.”
“Routing can be done using a number of network protocols but
the IP protocol is the one that is addressed in this article. IP is
also the protocol used on the Internet. The previous articles
address configuration of the IP protocol for network adapters on a
Linux computer.“