Linux Networking Cookbook

Chapter 1. Introduction to Linux Networking

1.0. Introduction

Computer networking is all about making computers talk to each other. It is simple to say, but complex to implement. In this Introduction, we'll take a bird's-eye view of Ethernet networking with Linux, and take a look at the various pieces that make it all work: routers, firewalls, switches, cabling, interface hardware, and different types of WAN and Internet services.

A network, whether it is a LAN or WAN, can be thought of as having two parts: computers, and everything that goes between the computers. This book focuses on connectivity: firewalls, wireless access points, secure remote administration, remote helpdesk, remote access for users, virtual private networks, authentication, system and network monitoring, and the rapidly growing new world of Voice over IP services.

We'll cover tasks like networking Linux and Unix boxes, integrating Windows hosts, routing, user identification and authentication, sharing an Internet connection, connecting branch offices, name services, wired and wireless connectivity, security, monitoring, and troubleshooting.

Connecting to the Internet

One of the biggest problems for the network administrator is connecting safely to the Internet. What sort of protection do you need? Do you need expensive commercial routers and firewalls? How do you physically connect your LAN to the Internet?

Here are the answers to the first two questions: at a minimum, you need a firewall and a router, and no, you ...