The Cisco CLI is the command-line interface you have been using since the beginning of your training.
As a network administrator, you must know how to use it correctly and confidently.In this section, the goal is simple:
👉 Get comfortable with the Cisco CLI and start typing more commands.
When you are ready, mark this step as complete.
Answer the question below
To use the Cisco CLI correctly, there is one important thing to understand:
Cisco organizes the CLI into different modes.Each mode has a specific role.
Each mode allows specific actions.User EXEC Mode
This is the default mode.
When you open the CLI, you start here.Switch>In this mode:
you can check basic information,
you cannot change the configuration.
This is a read-only mode.
From here, we can move to a higher mode.
Privileged EXEC Mode
To enter this mode, type the
enablecommand:Switch> enable Switch#This mode allows you to:
check important information about the device,
verify the current configuration,
restart or troubleshoot the device,
save the configuration.
As a network administrator, this mode is important.
You will use it often to verify that everything is working correctly.Global Configuration Mode
Now, we want to configure the device.
To do this, we need to enter the Global Configuration Mode.
By using theconfigure terminalcommand:Switch# configure terminal Enter configuration commands, one per line. Switch(config)#This is where all major configurations start.
In the previous lessons, you already entered this mode, even if you did not realize it at the time.Now, let’s imagine we want to activate a switch interface.
To do this, we need to use a sub-configuration mode.Sub-Configuration Modes
From global configuration mode, you can enter sub-configuration modes by using the appropriate command.
For example, use theinterface fastEthernet0/1command.Switch(config)# interface fastEthernet0/1 Switch(config-if)# → interface configurationYou are now in the interface configuration mode for fastEthernet0/1.
In this mode, you can configure the interface as needed.Activating the Interface
To activate the interface, use the
no shutdowncommand:Switch(config-if)# no shutdown %LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up Switch(config-if)#This output means that the interface
FastEthernet0/1is now active.
Great job!How to Move Between Cisco IOS Modes
Cisco IOS uses commands to move between modes.
The image below shows how the different modes are connected.
Figure 1 - Move between Cisco IOS Modes
How to Move Back Between Cisco IOS Modes
You are currently in Switch(config-if)#
To go back to the Switch# prompt, use theexitcommand.Switch(config-if)# exit Switch(config)# exit %SYS-5-CONFIG_I: Configured from console by console Switch#Each
exitcommand moves you back one mode at a time.When you leave Global Configuration Mode, the switch displays a message in the CLI to confirm the change.
Always look at the prompt to know where you are.Answer the question below
Which command lets you enter Global Configuration Mode?
Now that you have learned how to navigate the command line interface (CLI),
I should mention that Cisco devices do not automatically save your work.Cisco uses two configuration files within the network device, with each file stored in a different memory area.
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Figure 2 - Startup Config Vs Running Config
Startup Configuration (NVRAM)
This is the configuration that loads every time the device boots.
It is persistent.
It lives in NVRAM.
It doesn’t change unless you save manually.
Running Configuration (RAM)
This is the configuration currently active on the device.
It is stored in RAM.
Every command you type affects the running-config.
It disappears when the device reboots unless you save it.
You can view it using:
Switch# show running-config Building configuration... Current configuration : 1080 bytes ! version 15.0 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname Switch ! ! ! ! ! ! spanning-tree mode pvst spanning-tree extend system-id ! interface FastEthernet0/1 ! interface FastEthernet0/2 ! interface FastEthernet0/3 ! interface FastEthernet0/4 ! interface FastEthernet0/5 ! interface FastEthernet0/6 ! interface FastEthernet0/7 ! interface FastEthernet0/8 ! interface FastEthernet0/9 ! interface FastEthernet0/10 ! interface FastEthernet0/11 ! interface FastEthernet0/12 ! interface FastEthernet0/13 ! interface FastEthernet0/14 ! interface FastEthernet0/15 ! interface FastEthernet0/16 ! interface FastEthernet0/17 ! interface FastEthernet0/18 ! interface FastEthernet0/19 ! interface FastEthernet0/20 ! interface FastEthernet0/21 ! interface FastEthernet0/22 ! interface FastEthernet0/23 ! interface FastEthernet0/24 ! interface GigabitEthernet0/1 ! interface GigabitEthernet0/2 ! interface Vlan1 no ip address shutdown ! ! ! ! line con 0 ! line vty 0 4 login line vty 5 15 login ! ! ! ! endSaving Your Configuration
In order to save your changes, you must manually copy the 'running-config' to the 'startup-config' using the following command:
Switch# copy running-config startup-config Destination filename [startup-config]? Building configuration... [OK]or you can also use this command:
Switch# write memory Building configuration... [OK]If you forget this step, all your work is lost after a reboot, a very common mistake for beginners.
Answer the question below
Where is the running configuration stored?