Cisco CLI Basics Lab

In this lab, you learn how to navigate the Cisco IOS command-line interface and use it efficiently.
You will work directly inside Packet Tracer, interacting with a Cisco switch step by step.

Figure 1 – Network Topology

This is the topology used for the lab: a simple setup with one switch and one PC to keep the focus on the CLI itself.

How to Begin

Download the Packet Tracer file at the top of the page and open it.
The topology is already prepared, your goal is to explore the Cisco CLI and configure the device step by step.

Lab Overview

Here is the structure we will follow:

• Step 1 – Access the CLI

• Step 2 – Explore the CLI Help System

• Step 3 – Configure the Switch Hostname

• Step 4 – Configure an Interface

• Step 5 – Save the Configuration

• Step 6 – Verify Your Work and fix incorrect settings

I will guide you through each step and help you practise, so...

Let's begin!

To begin the lab, click on the switch in Packet Tracer to open the device window.

Figure 2 - Click on the Cisco Switch

Once the device window is open, you can access the CLI by selecting the CLI tab.

Figure 3 - Click on the CLI

You will now see the Cisco IOS prompt:

Figure 4 - Cisco CLI

Now we can explore the different CLI modes together.

User EXEC Mode

By default, you start in User EXEC mode.

Switch>

In this mode, you can only run basic monitoring commands.
No configuration is allowed here.

Let’s move on to the next mode.

Privileged EXEC Mode

You can enter Privileged EXEC mode by using the enable command:

Switch> enable
Password: 

As you may have notice a password is needed to pass.
This switch already has an enabled password configured. You must enter the password: cisco.

If the password is correct, the prompt changes to:

Switch#

You can recognize the Privileged EXEC Mode by the # symbol.
Here, you can run powerful informational commands such as show ip interface brief, show vlan, or show running-config.

Next, let’s see how to start configuring the device.
To do this, we need to enter Global Configuration mode.

Global Configuration Mode

Use the configure terminal command to access configuration mode:

Switch# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)# 

You can recognize this mode by the (config)# prompt.
This mode allows you to configure the device, which is where it gets interesting.

mais avant de tous configurer! Il faut que tu pratiques les aides du cli ça t'aidera grandement quand tu vas configurer.

Exit the Global Configuration Mode

Pour qu'on regarde les cli help system on va quitter le global config mode et revenir au privilege exec mode

Switch(config)# exit
Switch#

Parfait allons au prochain step maintenant

Cisco IOS provides several built-in helpers that guide you while typing commands.

The Question Mark (?)

The ? keyword shows you a list of the available commands in the current mode.

Switch# ?
Exec commands:
  clear       Reset functions
  clock       Manage the system clock
  configure   Enter configuration mode
  connect     Open a terminal connection
  copy        Copy from one file to another
  debug       Debugging functions (see also 'undebug')
  delete      Delete a file
  dir         List files on a filesystem
  disable     Turn off privileged commands
  disconnect  Disconnect an existing network connection
  enable      Turn on privileged commands
  erase       Erase a filesystem
  exit        Exit from the EXEC
// OUTPUT OMITTED FOR BREVETY

Try exploring deeper levels. If we take the command show and add the keyword ?, we can see the commands after the show command.

Switch# show ?
  aaa                Show AAA values
  access-lists       List access lists
  arp                Arp table
  boot               show boot attributes
  cdp                CDP information
  clock              Display the system clock
  crypto             Encryption module
  dhcp               Dynamic Host Configuration Protocol status
  dtp                DTP information
  etherchannel       EtherChannel information
// OUTPUT OMITTED FOR BREVETY

IOS always tells you what the next possible keyword is.

Switch# show ip ?
  access-lists  List access lists
  arp           IP ARP table
  dhcp          Show items in the DHCP database
  interface     IP interface status and configuration
  ssh           Information on SSH

You will use this constantly when you’re unsure about a command.

Switch# show ip interface ?
  Vlan   Catalyst Vlans
  brief  Brief summary of IP status and configuration
  |      Output Modifiers
  

TAB Completion

Pressing the Tab key automatically completes a command when iOS can guess what you want to type.

For example, you can write conf and then press Tab to complete the command. The CLI will then fill in the whole word, giving you configure

Switch# conf
Switch# configure

If you type configure ter and press the Tab key, the command will be completed for you.

Switch# configure ter
Switch# configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#

This saves time and prevents typing errors.

Command History (↑ / ↓)

To show you the history commands, we will return to the privileged exec mode.

Switch(config)# exit
Switch#

The CLI remembers the commands you typed earlier in the same mode.

• ↑ recalls recalls the previous command.

• ↓ moves forward in your history.

Try it and you will see commands that you have already typed before.

This is useful when verifying configurations or repeating similar commands.
Now that you know how to use these tools, let's continue configuring the switch.

Now that you know how to access configuration mode, you can apply your first real changes to the device.

Enter Global Configuration mode

We will begin by renaming the switch.
First, go into Global Configuration Mode.

Switch# conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#

You can use the conf t command, which is a shortcut for configuration terminal.
This command is very well-known and will allow you to access configuration mode more quickly.

Configure Hostname

Use the hostname command followed by the name you want the device to use.

In our case, we will name it SW1:

Switch(config)# hostname SW1
SW1(config)#

As soon as you press ENTER, the prompt will update to confirm that the hostname has been applied successfully.

Our switch is connected to PC1 via FastEthernet0/1 (F0/1).
It is good practice to add a description to the interface, so that anyone reading the configuration can immediately understand what the port is used for.

Enter interface configuration mode:

SW1(config)# interface f0/1
SW1(config-if)# description Connection to PC1

Great, the interface now has a clear and meaningful description!

Enable the Interface

We now need to enable the interface.
We can activate the port using the no shutdown command:

SW1(config-if)# no shutdown
SW1(config-if)# end
SW1#

You should immediately see messages indicating that the interface is now active.

%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up

After a short while, the small icon next to the interface will turn green to confirm that the link is operational.

Figure 5 - Interface is UP (Green)

Now that you have practised entering your first configuration commands, I will show you how to save the configuration in the next step.

Your switch is now correctly configured with a hostname and an active interface.
However, Cisco devices do not save the configuration automatically.
All of your work so far is stored in the running configuration, which will be lost if the device reloads.

To make your work permanent, you must save it manually.

Use one of the commands below:

SW1# write memory
Building configuration...
[OK]

or:

SW1# copy running-config startup-config 
Destination filename [startup-config]? 
Building configuration...
[OK]

Your changes have now been safely stored in NVRAM and will be retained after a reboot.

Let’s take a look at the running configuration.
As you already know, Cisco IOS doesn’t require you to type full commands. As long as your input is unambiguous, the device understands it.

To display the running configuration, you could type the full command show running-configuration.
But we’ll use the very common shortcut show run, which does exactly the same thing.

SW1# show run
Building configuration...

Current configuration : 1132 bytes
!
version 15.0
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname SW1
!
enable password cisco
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
interface FastEthernet0/1
 --More-- 

Understanding the --More-- Prompt

You can now see a portion of the running configuration.
At the bottom, the --More-- message indicates that the output is not finished yet.

To continue displaying the configuration, you have two options.

Scrolling Line by Line (Enter)

If you press Enter, IOS shows one additional line:

interface FastEthernet0/1
 description Connection to PC1
 --More-- 

This moves slowly through the output, one line at a time.

Scrolling One Page at a Time (Space Bar)

To go faster, you can press the Space bar, which displays a full page at once:

interface FastEthernet0/1
 description Connection to PC1
!
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
 --More-- 

This allows you to scroll through the entire running configuration much more quickly.
Keep pressing the Space bar until you reach the end of the output, marked by the line end.

Reviewing the Running Configuration

SW1# show run
Building configuration...

Current configuration : 1132 bytes
!
version 15.0
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname SW1
!
enable password cisco
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
interface FastEthernet0/1
 description Connection to PC1
!
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
!
!
!
!
end

As you can see, the running configuration now includes everything we configured earlier.

The hostname and the description on interface FastEthernet0/1 appear correctly.
However, one line stands out and should not be there:

enable password cisco

Using enable password is not secure.
Because the password is stored in clear text, anyone who views the running configuration can read it directly. This is something we absolutely want to avoid.

To fix this, we will remove the insecure password.

Removing the Insecure Password

Return to global configuration mode with conf t and delete it:

SW1# conf t
Enter configuration commands, one per line.  End with CNTL/Z.
SW1(config)# no enable password

Now we can configure a secure password that will not appear in plain text in the running configuration:

SW1(config)# enable secret PingMyNetwork-CCNA
SW1(config)# end
SW1#
%SYS-5-CONFIG_I: Configured from console by console

Verifying the New Encrypted Password

Let’s verify the result:

SW1# show run
Building configuration...

Current configuration : 1157 bytes
!
version 15.0
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname SW1
!
enable secret 5 $1$mERr$3scxFNdBMuOzwvk6yHQMA.
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
interface FastEthernet0/1
 --More-- 

Perfect, the password is no longer displayed in clear text.
Cisco IOS automatically encrypts the value of enable secret, so the original password cannot be read from the configuration.

You can press Q to exit the output immediately without scrolling through the rest of the configuration.

Finally, save your running configuration now that all changes have been applied:

SW1# write memory 
Building configuration...
[OK]

Great job!

Congratulations on completing the IOS Basics Lab!

You now know how to:

• navigate between IOS modes

• use help, history, and shortcuts

• configure basic switch settings

• verify and save your work

• remove incorrect configurations

These skills form the foundation for all upcoming CCNA labs, including VLANs, trunking, STP, DHCP, and routing.