routing is what allows the large number of individual networks around

routing is what makes all the networks around the world connect with each other.

a router is a computer or special hardware device that directs data between parts of a network and between different networks. companies can use routers to connect their internal networks to the internet as well as to connect their networks inside the company.

linux is a good choice for this functions at it provides support for routing and is easily customizable. there are many linux distributions that can fit on a single floppy disk and provide routing capabilities

and example of a small router is the LINUX ROUTER PROJECT, which you can download for free at the following url:
www.linuxrouter.org

try it