Chapter 1. Introduction

Who cares about configuring network routers? Network routers are a major part of the glue that holds all computer networks together. Routers are supposed to configure themselves right? Not really. Routers aren't to the point of being able to configure themselves, yet. They have no artificial intelligence agent so almost everything on them must be done manually. That's where you and I come in. So I guess you and I care about configuring network routers. Since almost every network is different, we as network engineers and administrators must know our networks and configure our routers to become a part of our network infrastructure.

  1. You Should Read This Book

    2. You are about to find out how all those highly-paid (or so they say) network engineers managed to get all of your company's computers talking to each other using Cisco IOS-based routers. The subject matter here is meant for the network administrator or network engineer who understands general computer networking and who needs to configure Cisco routers to provide basic connectivity for networks running multiple protocols. You will see that configuring IOS to perform basic routing and bridging of network messages is pretty easy; it can be done by learning and putting into practice just a few basic commands. Of course, IOS configuration is not always intuitive; that's why you need this book.

  2. What This Book Is

    3. The purpose of this book is to get you started in configuring Cisco IOS-based routers. This book is meant to be a tutorial for the person new to the Cisco IOS as well as a basic reference for the somewhat experienced IOS person. We'll be covering several hundred IOS commands. No one expects you to remember all of the commands; however, there are a few you absolutely must know. I will be sure to indicate which ones those are as we go along.

    This book is also a task-oriented programmer's reference for the Cisco IOS. We will show the commands in the context in which they are most often used. We're going to cover the very basic configuration of the major routing and bridging features of the Cisco IOS.

  3. What This Book Isn't

    4. This book is not meant to be a study of computer networking nor is it meant to provide in-depth details on network protocols. Rather it is simply a reference for the basic configuration of Cisco IOS-based routers

  4. Game Plan

We're going to start out slowly with a brief description of network routing and how the Cisco IOS fits into the big picture. After the routing description, we'll cover configuring a brand new Cisco router right out of the box to be installed into an existing network. We're going to use the standard IOS Setup facility to do this the first time. Thereafter, we'll use the IOS Command Line Interface to do the same thing and more. The Cisco 2500-series routers will be used in the examples, but the IOS configuration principles that will be shown work for all of the Cisco IOS-based router models from the 1000 to the 12000. There are some minor differences, but we'll cover those when we get to them.

We will use a task-oriented procedure to group the commands for configuring many IOS routing and bridging features. The configuration of each network protocol, such as IP and IPX, will be presented as a task. Each protocol will be covered with the following steps:

    • A brief overview of how the protocol works
    • Descriptions of the commands needed to turn on and configure the protocol
    • Examples showing the implementation of the commands
    • Commands used to make sure everything is working properly

The commands shown will be those that I consider to be the most used and most popular. Each IOS command will also be explained in detail in programmer's reference sections.

    1. Chapter Overview

      2. Following is a list of the rest of the chapters along with a brief description of what is covered in each one:

      Chapter 2, Routing and Bridging Overview, covers router operation and provides an introduction to Cisco IOS.

      Chapter 3, Initial Configuration, shows the configuration of a Cisco IOS-based router from scratch using the IOS Setup facility. No special command knowledge is required.

      Chapter 4, IOS Command Line Interface, explains the primary means of configuring the IOS - typing commands into its command line interface.

      Chapter 5, Examining IOS, could also be called "As long as we're here, we might as well look around." We use the most-used command in IOS, show, to examine the main components of the IOS-based router.

      Chapter 6, General IOS Tasks, provides the first detailed look at IOS configuration before we get into configuring IOS to process network traffic. Other tasks such as managing configuration files and resetting interfaces are also here.

      Chapter 7, Configuring IP, provides the commands needed to tell our router to start routing IP packets. It covers addressing of interfaces and IP interior routing protocol configuration.

      Chapter 8, Configuring IPX, provides the commands needed to tell our router to start routing Novell IPX packets.

      Chapter 9, Configuring AppleTalk, provides the commands to start AppleTalk on our router.

      Chapter 10, Configuring DECnet, provides the commands necessary to start DECnet on our router. It includes a brief overview of DECnet.

      Chapter 11, Configuring VINES, provides coverage of the commands for configuring Banyan VINES on our router.

      Chapter 12, Configuring Transparent Bridging, covers the commands for turning our router into a bridge and why we need them.

      Chapter 13, Configuring Source Route Bridging, provides the commands for configuring this special type of token-ring bridging that comes to us courtesy of IBM.

      Chapter 14, Configuring Other IBM Connectivity, provides the commands for doing RSRB, DLSw, and other IOS ways of handling IBM traffic over a WAN.

      Appendix A, Command Reference, provides a list of all of the IOS commands used in the book. Each command is cross-referenced to the page where it appears.

      Appendix B, Acronym Glossary, provides a list of all of the acronyms used in the book. After all, we networking folks do have a tendency to speak our own language of acronyms.

    2. Conventions

The parts of a command that should be typed as shown will be indicated by boldface. Command arguments that require a value will be shown in Italics. Optional arguments of a command will be shown within brackets ([ ]). When multiple entries are possible, but only one is allowed, the entries will be separated by a vertical bar (|). When multiple entries are possible, but one is required, the choices will be shown within braces ({ }). These designations can be combined to represent the syntax requirements of a command.

Text produced by the router will be displayed in a constant-width font. Typed text entries will be displayed in boldface.

For the depiction of multiple keys being pressed simultaneously, the key symbols will be placed together within angle brackets and separated by hyphens, for example, <Ctrl-Shift-6> means that the Ctrl key, the Shift key, and the 6 key should be pressed at the same time.

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