Exercise: CUPS Service Check and Access

Exploring the Linux Print Server

A hands-on exercise to verify the CUPS service is running on Fedora and to access its powerful web-based administration interface.
Author

Chuck Nelson

Published

November 16, 2025

1 Purpose

This exercise introduces you to the Common Unix Printing System (CUPS), the core print server on Linux. Before you can add or manage printers, you must first confirm that the service is running and know how to access its primary administration tool: the web interface. This provides a foundation for all subsequent printer management tasks.

2 What You’ll Accomplish

By the end of this exercise, you will be able to:

  • Use systemctl to check the status of the CUPS service.
  • Describe and observe the behavior of a socket-activated service.
  • Access the CUPS web administration interface using a browser.

This exercise maps to the following program and course learning outcomes:

  • Course Learning Outcomes (CLOs):
    • 3. Troubleshoot hardware and basic network components: Verifying that a required service is running is a fundamental troubleshooting step.

This exercise develops the following skills, which align with the O*NET SOC Code 15-1232.00 for Computer User Support Specialists.

Learning Objective O*NET KSAs Technologies Used
Check status and access the CUPS interface. Knowledge: Computers & Electronics
Skills: Systems Analysis		 CUPS, systemd, systemctl

3 Prerequisites

This exercise requires a running Fedora 43 virtual machine with sudo privileges.

4 Step-by-Step Guide

Open a terminal window in your Fedora VM to begin.

4.1 Step 1: Check the Initial CUPS Status

On modern Linux systems, many services are socket-activated. This means the service doesn’t run all the time; it is only started automatically by systemd when a program tries to connect to it. Let’s observe this.

  1. Run the systemctl status command:

    sudo systemctl status cups

  2. Analyze the Output: Look at the Active: line. It is very likely to say inactive (dead). This is normal! It simply means nothing has needed to use the printing system yet. You can also see cups.socket listed, which is the key to its activation.

4.2 Step 2: Trigger Socket Activation

Now, we will perform an action that requires the CUPS service: accessing its web interface. This will cause systemd to start the service automatically.

  1. Open the Firefox browser in your VM.

  2. In the address bar, type the following and press Enter:

    http://localhost:631

  3. The page should load, showing you the main CUPS administration page. In the background, systemd has just started the cups service to handle your browser’s request.

4.3 Step 3: Verify the New Service Status

Let’s go back to the terminal and check the status again.

  1. Run the same status command as before:

    sudo systemctl status cups

  2. Analyze the New Output: Look at the Active: line again. It should now say active (running). You have just witnessed socket activation in action!

  3. Explore the Interface: Click on the different tabs at the top of the web page, such as Administration, Printers, and Jobs. Note that you can see server settings, add new printers, and manage print queues directly from this interface.

5 Reflect and Review

ImportantReflection: 3-2-1

Now that you have completed this exercise, reflect on your experience in your personal notes:

  • 3 of the tabs you saw in the CUPS web interface.
  • 2 different statuses you observed for the CUPS service (inactive and active).
  • 1 question you still have about socket activation.
TipCheck on Learning

Answer these questions in your notes to solidify your understanding:

  1. What is CUPS?
  2. What does it mean for a service to be “socket-activated”?
  3. What address do you navigate to in a web browser to access the CUPS administration page?
  4. What action caused the cups service to change from inactive to active?
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