Hi there! Today, we’re diving into the basics of Cisco CLI (Command Line Interface). Networking theory is essential, but practical knowledge of configuring network equipment is where the magic happens. Many of us have a solid understanding of concepts but feel lost when faced with real-world network configurations. So, let’s bridge that gap and explore how networks actually work in practice.
We’ll start by understanding what Cisco CLI is and why it’s a crucial tool for network administrators. Then, we’ll cover some basic commands and their purposes, helping you take the first step toward mastering network configurations.
What is Cisco CLI?
The Cisco Command Line Interface is a powerful tool used to manage and configure Cisco networking devices, such as routers and switches. It’s a text-based interface that allows you to interact with devices using typed commands. Unlike GUIs (Graphical User Interfaces), the CLI offers granular control and is a preferred method for many networking professionals.
Getting Started: Connecting to a Cisco Device
To start using the CLI, you’ll need access to a Cisco device. This is typically done via:
- Console Port: Using a console cable and terminal software (e.g., PuTTY).
- SSH or Telnet: If the device is already configured for remote access.
We are going to use Cisco Packet Tracer, so you can emulate the connection above or simply double-click the equipment and then click on CLI.
Once connected, you’ll see a prompt like the one above. At this point, you can proceed with the configuration wizard, but since we are learning the basics, let’s select “no” and configure it manually. 😊
Once you select “no,” you’ll see a prompt like this:
This is the user EXEC mode, which offers limited access. To configure the device, you’ll need to enter the privileged EXEC mode using the enable command:
The # symbol indicates you’re now in privileged EXEC mode.
Basic Commands to Get You Started
show version: Displays system information, including software version and hardware details.show ip interface brief: Provides a summary of interfaces and their statuses.configure terminal: Enters the global configuration mode to make changes.interface [interface-name]: Configures a specific interface (e.g.,interface gigabitEthernet 0/0).ip address [IP] [subnet-mask]: Assigns an IP address to an interface.no shutdown: Activates an interface.
A Simple Example: Setting Up an IP Address on an Interface
Here’s a quick walkthrough of configuring an IP address on an interface:
- Enter global configuration mode with the command
configure terminal:
- Select the interface with
interface gigabitEthernet 0/0:
- And let’s assign an IP address and subnet mask to that adapter using the command
ip address (IP ADDRESS) (NETMASK):
- Lastly, activate the interface with the
no shutdowncommand:
Now you can verify the configuration using the show ip interface brief or show running commands, but you need to be two levels up. To do this, simply use the exit command until you see the # prompt.
And that’s it! You have successfully configured an interface on a Cisco router. Congratulations! 😊 Stay tuned for another configuration walkthrough!
