Linux is a perfect platform to act as a router/gateway.
In this tutorial, I will explain how to set up a Linux box to operate as a network router. The box will provide the following services:
* DHCP server to provide the ip addresses to the machines in the LAN
* DNS server to resolve domain names
* Gateway with IP tables to give access to the Internet.
* Firewall with IP tables.
The resulting machine will have quite a small footprint: about 600M, and except if your network is intensively used, a low spec computer can be recycled to do the job.
As the machine is going to operate as a router/firewall