To configure devices, the CLI is divided into various command modes. Each command mode has its own set of specific commands. Entering a question mark “?” at the console prompt displays a list of commands available for that particular command mode.

A specific command, which varies from mode to mode, is used to navigate from one mode to another. The standard order to access the modes is as follows: User EXEC mode, Privileged EXEC mode, Global Configuration mode, and Interface Configuration modes.

When starting a session, the initial mode for non-privileged users is the User EXEC mode. Only a limited subset of commands is available in the User EXEC mode. This level is reserved for tasks that do not change the configuration.

Privileged users enter the Privileged EXEC mode directly using a password. This mode provides access to the device Configuration modes.

The modes are described below.

User EXEC Mode

After logging into the device, the user is automatically in User EXEC command mode unless the user is defined as a privileged user. In general, the User EXEC commands enable the user to perform basic tests, and display system information.

The user-level prompt consists of the device “host name” followed by the angle bracket (>).

console>

The default host name is “console” unless it has been changed using the hostname command in the Global Configuration mode.

Privileged EXEC Mode

Privileged access is password-protected to prevent unauthorized use, because many of the privileged commands set operating system parameters: The password is not displayed on the screen and is case sensitive.

Privileged users enter directly into the Privileged EXEC mode.

Use disable to return to the User EXEC mode.

Global Configuration Mode

Global Configuration mode commands apply to features that affect the system as a whole, rather than just a specific interface.

To enter the Global Configuration mode, enter configure in the Privileged EXEC mode, and press <Enter>.

The Global Configuration mode prompt is displayed.

console(config)#

Use exit, end or ctrl/z to return to the Privileged EXEC mode.

Interface Configuration Modes

Commands in the following modes perform specific interface operations:

• Line Interface —Contains commands to configure the management connections. These include commands such as line speed, timeout settings, etc. The Global Configuration mode command line is used to enter the Line Configuration command
• VLAN Database —Contains commands to create a VLAN as a whole. The Global Configuration mode command vlan database is used to enter the VLAN Database Interface Configuration
• Management Access List —Contains commands to define management access-lists. The Global Configuration mode command management access-list is used to enter the Management Access List Configuration
• Port Channel —Contains commands to configure port-channels, for example, assigning ports to a VLAN or port-channel. The Global Configuration mode command interface port-channel is used to enter the Port Channel Interface Configuration
• SSH Public Key-Chain —Contains commands to manually specify other device SSH public keys. The Global Configuration mode command crypto key pubkey-chain ssh is used to enter the SSH Public Key-chain Configuration
• Interface —Contains commands that configure the interface. The Global Configuration mode command interface is used to enter the Interface Configuration