An Introduction to TCP/IP
Perhaps the greatest advantage of Linux (and UNIX, in general) is its flexibility, especially with respect to networking. It was designed to make access easy; its use of Transmission Control Protocol/Internet Protocol (TCP/IP) networking is in harmony with that design perspective. In this chapter, we will take a look at networking from an overview perspective and introduce the TCP/IP model. We will also make a number of definitions and introduce a number of concepts that we will use throughout this book.
Networks connect things together. The collection of roads throughout the United States comprises a network of paths by which vehicles can reach various points. The purpose of a network of roads is to permit people to efficiently move from one place to another. Computer networks consist of interconnected computer systems. The purpose of networking these components together is to share information and computing resources. An obvious example of a computer network is the Internet, in which millions of people access information and computer resources throughout the world. Most of the folks utilizing these resources have little notion of how those resources are made available to them or what tasks are required to provide such resources. That, after all, is the job of some computer jockey - or more formally, a system and/or network administrator.
System and network administrators own the task of ensuring that computer resources remain available. While the tasks of these two distinct roles often overlap, it is the job of the network administrator to ensure that computers and other dedicated network devices, such as repeaters, bridges, routers, and application servers, remain interconnected. In order to accomplish this task, the network administrator needs to be familiar with the software and hardware employed to effectively connect the various components. This familiarity must begin with the concept of network types and models.