Chapter 1. Overview of TCP/IP

All of us who use a Unix desktop systemengineers, educators, scientists, and business peoplehave second careers as Unix system administrators. Networking these computers gives us new tasks as network administrators.

Network administration and system administration are two different jobs. System administration tasks such as adding users and doing backups are isolated to one independent computer system. Not so with network administration. Once you place your computer on a network, it interacts with many other systems. The way you do network administration tasks has effects, good and bad, not only on your system but on other systems on the network. A sound understanding of basic network administration benefits everyone.

Networking your computers dramatically enhances their ability to communicateand most computers are used more for communication than computation. Many mainframes and supercomputers are busy crunching the numbers for business and science, but the number of these systems in use pales in comparison to the millions of systems busy moving mail to a remote colleague or retrieving information from a remote repository. Further, when you think of the hundreds of millions of desktop systems that are used primarily for preparing documents to communicate ideas from one person to another, it is easy to see why most computers can be viewed as communications devices.

The positive impact of computer communications increases with the number and type of computers that participate in the network. One of the great benefits of TCP/IP is that it provides interoperable communications between all types of hardware and all kinds of operating systems.

The name "TCP/IP" refers to an entire suite of data communications protocols. The suite gets its name from two of the protocols that belong to it: the Transmission Control Protocol (TCP) and the Internet Protocol (IP). TCP/IP is the traditional name for this protocol suite and it is the name used in this book. The TCP/IP protocol suite is also called the Internet Protocol Suite (IPS). Both names are acceptable.

This book is a practical, step-by-step guide to configuring and managing TCP/IP networking software on Unix computer systems. TCP/IP is the leading communications software for local area networks and enterprise intranets, and it is the foundation of the worldwide Internet. TCP/IP is the most important networking software available to a Unix network administrator.

The first part of this book discusses the basics of TCP/IP and how it moves data across a network. The second part explains how to configure and run TCP/IP on a Unix system. Let's start with a little history.