Understanding Command Modes
The command modes available in Cisco IOS XE are the same as those available in traditional Cisco IOS. Use the CLI to access Cisco IOS XE software. Because the CLI is divided into many different modes, the commands available to you at any given time depend on the mode that you are currently in. Entering a question mark (?) at the CLI prompt allows you to obtain a list of commands available for each command mode.
When you log in to the CLI, you are in user EXEC mode. User EXEC mode contains only a limited subset of commands. To have access to all commands, you must enter privileged EXEC mode, normally by using a password. From privileged EXEC mode, you can issue any EXEC command—user or privileged mode—or you can enter global configuration mode. Most EXEC commands are one-time commands. For example, show commands show important status information, and clear commands clear counters or interfaces. The EXEC commands are not saved when the software reboots.
Configuration modes allow you to make changes to the running configuration. If you later save the running configuration to the startup configuration, these changed commands are stored when the software is rebooted. To enter specific configuration modes, you must start at global configuration mode. From global configuration mode, you can enter interface configuration mode and a variety of other modes, such as protocol-specific modes.
ROM monitor mode is a separate mode used when the Cisco IOS XE software cannot load properly. If a valid software image is not found when the software boots or if the configuration file is corrupted at startup, the software might enter ROM monitor mode.
The following table describes how to access and exit various common command modes of the Cisco IOS XE software. It also shows examples of the prompts displayed for each mode.
Command Mode |
Access Method |
Prompt |
Exit Method |
---|---|---|---|
User EXEC |
Log in. |
|
Use the logout command. |
Privileged EXEC |
From user EXEC mode, use the enable command. |
|
To return to user EXEC mode, use the disable command. |
Global configuration |
From privileged EXEC mode, use the configure terminal command. |
|
To return to privileged EXEC mode from global configuration mode, use the exit or end command. |
Interface configuration |
From global configuration mode, specify an interface using an interface command. |
|
To return to global configuration mode, use the exit command. To return to privileged EXEC mode, use the end command. |
Diagnostic |
The router boots up or accesses diagnostic mode in the following scenarios:
|
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If failure of the Cisco IOS process is the reason for entering diagnostic mode, the Cisco IOS problem must be resolved and the router rebooted to get out of diagnostic mode. If the router is in diagnostic mode because of a transport-map configuration, access the router through another port or by using a method that is configured to connect to the Cisco IOS CLI. |
ROM monitor |
From privileged EXEC mode, use the reload EXEC command. Press the Break key during the first 60 seconds while the system is booting. |
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To exit ROM monitor mode, manually boot a valid image or perform a reset with autoboot set so that a valid image is loaded. |