Router CLI Modes explained- Part 1 | CCNA 200-301

Notes-:

Cisco Command Line Interface (CLI) is the main interface where we will interact with Cisco IOS devices.
From CLI we can do monitor device status or chang configuration.
Cisco has divided its CLI into several different modes. Understanding Cisco IOS Command Line Modes is essential as Each of these modes serves a different purpose and has its own set of commands.

CLI modes are as follows.
1.Setup Mode
2.Command Mode
a.User mode
b.Privileged Mode
c.Configuration modes
3.Rommon Mode
When we power-on the IOS operated device, It loads the functional IOS and then looks for the device configuration.
If it does not find a valid configuration, it places the user in the mode known as setup mode.
Setup mode
This mode allows the user to configure the initial device configuration.
This mode presents a text-based wizard that asks questions about initial settings in the sequence.
Based on the answers provided by the user, the IOS automatically builds the initial configuration.
Once the initial configuration is done or if the configuration is already present in the router a user will end up directly into the user mode
1.User mode
The user mode is the default mode for the CLI.
This is the first mode a user has access to after logging into the router.
This is the prompt you are placed in when you access the device using the console cable or Telnet / SSH from other node.
No matter how a user accesses the IOS, the IOS always places the user in this mode
This mode is the least privileged mode in IOS.
2. Privileged mode
As the name suggests, this mode includes privileged or powerful commands.
This mode allows users to
* To view, save and erase device configuration
* To take the backup of the current device configuration
* To restore the configuration from backup
* To install a new IOS image file
* To debug or troubleshoot the device
* To restart or reload the device

From privileged mode, you can access all the config command mode and sub modes.

Configuration mode
This is where the real configurations are done.
As the name suggests, this mode includes the commands that are used to configure the device.
A user can modify device configuration or running system configuration only from the configuration mode.
Configuration mode has various submodes, starting with
Global configuration mode,
In this mode you can make global changes to the device your are configuring, such as configure a new hostname, creating a user account, set up passwords, configure authentication, etc.
The commands in the global configuration mode usually apply to features that affect the system as a whole (hence the name global).
From global configure mode you can access various submodes
Interface Configuration Mode
This modes will be accessed to configure an interface on your device
The interface mode contains commands relevant to the interface being configured.
Router Configuration Mode
In this mode you can configure an IP routing protocol. so you can say it is Routing protocols configuration mode.
Line Configuration Mode
Line configuration mode commands allow you to configure the settings of vty ports
This virtual port allows telnet or ssh access to the device.
ROMMON Mode
To understand this mode we need to go back to the bootup process.
During the boot process, the IOS image file is loaded from flash into the RAM.
If the IOS image file is missing or corrupt, if it fails to load IOS the device automatically enters the mode known as rommon mode.
This mode allows the user to troubleshoot the IOS.
In this mode, the user can select a different IOS image file to boot the device or load a new IOS image file from the TFTP server.
You can manually enter in this mode for diagnostic purpose. This mode is also used for password recovery procedure.

#router #cli #ios #cisco #CCNA

source

ccna