Introduction

This document provides a summary of the commands used to configure routers. This book is divided into parts and chapters that correspond to Cisco IOS Command Reference modules and their chapters. Within each chapter the commands are listed in alphabetical order. The table of contents shows the parts and chapters in this book. Two indexes are provided: an index by command and an index by command type and command mode. The index by comman lists all the commands in alphabetical order. The index by type and command mode lists commands by types that roughly correspond to the chapters and then by command mode (for example EXEC, global configuration, and interface configuration). See the Cisco IOS Command Reference modules for complete command descriptions and examples.

Conventions

This document uses the following conventions:

• The symbol ^ and the text Ctrl represent the key labeled Control.

For example, the key combination ^D or Ctrl-D mean hold down the Control key while you press the D key.

• A string is defined as a nonquoted set of characters.

For example, when setting up a community string for SNMP to "public," do not use quotes around the string, or the string will include the quotation marks.

Command descriptions use the following conventions:

• Vertical bars ( | ) separate alternative, mutually exclusive, elements.

• Square brackets ([ ]) indicate optional elements.

• Braces ({ }) indicate a required choice.

• Braces within square brackets ([{ }]) indicate a required choice within an optional element.

• Boldface indicates commands and keywords that are entered literally as shown.

• Italics indicate arguments for which you supply values.

• If the no form of a command has exactly the same keywords and arguments as the command, no appears in square brackets at the beginning of the command line. If the no form of a command does not have all the same keywords and arguments, the no form is displayed separately.

• If the no form of a command is not explicitly explained in the description, it negates the command.

EXEC System Use

• Enter commands by typing their names at the EXEC prompt and pressing the Return key.

• There are two EXEC prompt levels. The user-level prompt is the server name followed by an angle bracket (>), as in this example:

  Router>

There is also a privileged-level prompt available to the system administrator by entering a password. It is the server name followed by a pound sign (#), as in this example:

  Router#

• Use the following editing commands when typing commands at the EXEC prompt:

  • Delete or Backspace to erase characters

  • Ctrl-U to delete a line

• As a shortcut, you can abbreviate commands to the fewest letters that make them unique. The letters "sho" can be entered for the show command, for example.

• Certain EXEC commands display multiple screens with this prompt at the bottom of the screen:

  --More--

Press the space bar to continue the output or press Return to display the next line. Press any other key to return to the prompt.

System Help

You can obtain help when entering commands by using the following methods:

• For a brief description of the context-sensitive help system, type help.

• To list all commands for a command mode, enter a question mark (?) at the system prompt.

• To obtain a list of commands that start with a particular character set, enter an abbreviated command immediately followed by a question mark (?).

• To list a command's keywords or arguments, enter a question mark (?) in place of a keyword or argument on the command line.

• At any time during an active Telnet session, you can list the Telnet commands by typing the following command at the system prompt:

Ctrl-^ ?

Press the Ctrl, Shift, and 6 keys simultaneously, let go, and type ?.