Cisco ASR 901 User Manual

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Cisco ASR 901 Aggregation Services Router Command Reference Guide
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Chapter 1 Using Command-Line Interface
Using the No and Default Forms of Commands
Using the No and Default Forms of Commands
Almost every configuration command has a no form. In general, enter the no form to disable a function.
Use the command without the keyword no to reenable a disabled function or to enable a function that is
disabled by default. For example, IP routing is enabled by default. To disable IP routing, specify the
no ip routing command and specify ip routing to reenable it. This publication provides the complete
syntax for the configuration commands and describes what the no form of a command does.
Configuration commands can have a default form. The default form of a command returns the command
setting to its default. Most commands are disabled by default, so the default form is the same as the no
form. However, some commands are enabled by default and have arguments that are set to certain default
values. In these cases, the default form of the command enables the command and sets arguments to
their default values. This publication describes what the default form of a command does if the
command is not the same as the no form.
Saving Configuration Changes
To save your configuration changes to your startup configuration so that they will not be lost if there is
a system reload or power outage, enter the following command:
Router# copy system:running-config nvram:startup-config
Building configuration...
It might take a minute or two to save the configuration. After the configuration has been saved, the
following output appears:
[OK]
Router#

Cisco ASR 901 Specifications

General

Form Factor	Rack-mountable
Operating Temperature	-40 to 65°C
Product Type	Aggregation Services Router
Rack Height	1 RU
Storage Temperature	-40 to 70°C
Humidity	5% to 95% non-condensing
Weight	4.5 kg
Power Supply	AC or DC
Compliance	RoHS, CE, FCC
Redundancy	Dual power supply option
MTBF	320, 000 hours

Summary

About This Guide

Document Revision History

Details technical changes made to the document across various releases.

Objectives

Explains the purpose and scope of the guide for Cisco ASR 901 Series routers.

Audience

Identifies the intended readers for this guide, focusing on networking professionals.

Conventions

Explains typographical conventions used in the document for clarity and consistency.

Related Documentation

Lists other Cisco documentation relevant to the ASR 901 Series router.

Obtaining Documentation and Submitting a Service Request

Provides information on how to access Cisco documentation and submit service requests.

Using Command-Line Interface

Getting Help

Describes how to use the question mark (?) and Tab key for context-sensitive CLI help.

How to Find Command Options

Explains how to display command syntax and find available keywords and arguments.

Understanding Command Modes

Details the different command modes in the Cisco IOS user interface and their access methods.

Using the No and Default Forms of Commands

Explains how to use 'no' and 'default' forms to disable or revert commands.

Saving Configuration Changes

Describes the procedure for saving running configuration changes to the startup configuration.