Cisco Systems 3560-X, 3750-X Understanding no and default Forms of Commands, Understanding CLI Error Messages, Using Configuration Logging

2-4
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 2 Using the Command-Line Interface
Understanding no and default Forms of Commands
Understanding no and default Forms of Commands
Almost every configuration command also has a no form. In general, use the no form to disable a feature
or function or reverse the action of a command. For example, the no shutdown interface 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.
Configuration commands can also 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 variables set to certain default
values. In these cases, the default command enables the command and sets variables to their default
values.
Understanding CLI Error Messages
Table 2-3 lists some error messages that you might encounter while using the CLI to configure your
switch.
Using Configuration Logging
You can log and view changes to the switch configuration. You can use the Configuration Change
Logging and Notification feature to track changes on a per-session and per-user basis. The logger tracks
each configuration command that is applied, the user who entered the command, the time that the
Tab le 2-3 Common CLI Error Messages
Error Message Meaning How to Get Help
% Ambiguous command:
"show con"
You did not enter enough characters
for your switch to recognize the
command.
Re-enter the command followed by a question mark (?)
with a space between the command and the question
mark.
The possible keywords that you can enter with the
command appear.
% Incomplete command. You did not enter all the keywords or
values required by this command.
Re-enter the command followed by a question mark (?)
with a space between the command and the question
mark.
The possible keywords that you can enter with the
command appear.
% Invalid input detected
at ‘^’ marker.
You entered the command
incorrectly. The caret (^) marks the
point of the error.
Enter a question mark (?) to display all the commands
that are available in this command mode.
The possible keywords that you can enter with the
command appear.