How to Use This Book

All the information in this book has been designed to follow a quick-reference format. If you know what feature or technology you want to use, you can turn right to the section that deals with it. Sections are numbered with a quick-reference index, showing both chapter and section number. For example, 13-3 is Chapter 13, Section 3. You'll also find shaded index tabs on each page, listing the section number corresponding to the topic covered for easier navigation through the book.

Facts About a Feature

Each section in a chapter includes a bulleted list of quick facts about the feature, technology, or protocol. Refer to these lists to quickly learn or review how the feature works. Immediately following, we have placed a note that details what protocol or port number the feature uses. If you are configuring filters or firewalls and you need to know how to allow or block traffic from the feature, look for these notes.

Configuration Steps

Each feature that is covered in a section includes the required and optional commands used for common configuration. The difference is that the configuration steps are presented in an outline format. If you follow the outline, you can configure a complex feature or technology. If you find that you don't need a certain feature option, skip over that level in the outline.

Sample Configurations

Each section includes an example of how to implement the commands and their options. We have tried to present the examples with the commands listed in the order you would actually enter them to follow the outline. Many times, it is more difficult to study and understand a configuration example from an actual router, because the commands are displayed in a predefined order, not in the order you entered them. Where possible, the examples have also been trimmed to show only the commands presented in the section.