Using the "No" Form of a Command

The no keyword is a specific form of an existing command and does not represent a new or distinct command. Almost every configuration command has a no form. In general, use the no form to reverse the action of a command or reset a value back to the default. For example, the no shutdown configuration command reverses the shutdown of an interface. Use the command without the keyword no to re-enable a disabled feature or to enable a feature that is disabled by default. Only the configuration commands are available in the no form.