Enhancing macOS Security: A Guide to Enabling and Configuring the Firewall

This comprehensive guide is specifically tailored for securing your personal home PC or Mac. It's essential to note that Seattle University's managed devices come equipped with state-of-the-art security measures pre-configured, ensuring an elevated level of protection by default.

Enabling the macOS firewall helps protect your computer from unauthorized incoming network connections. It can be an essential security measure to prevent unauthorized access to your system. To turn on the macOS firewall, follow these steps:

To enable the firewall on your Mac, follow these steps:

  1. Open System Settings:

    1. Click the Apple menu in the top-left corner of your screen.

    2. Select “System Settings” from the dropdown menu.

  2. Access Firewall Settings:

    1. In the System Settings window, click on “Network” in the sidebar.

    2. Scroll down and select “Firewall” on the right side.

  3. Enable the Firewall:

    1. Click the toggle switch to turn on the firewall.

For additional security configurations, click on “Options” within the Firewall settings. Here, you can:

  • Block all incoming connections: Prevent all incoming connections except those required for basic internet services.

  • Automatically allow built-in software to receive incoming connections: Permit built-in apps and services to receive incoming connections without your authorization.

  • Automatically allow downloaded signed software to receive incoming connections: Allow downloaded apps signed by a valid certificate authority to receive incoming connections.

  • Enable stealth mode: Prevent your Mac from responding to probing requests that can reveal its existence.

These settings provide granular control over your Mac’s network security.

For a visual guide on configuring the macOS firewall, you might find this video helpful:

https://youtu.be/bE2FhncKszQ?si=pMRBlRZlq-evJg11
  1. Click on the Apple logo in the top-left corner of your screen.

  2. Select "System Preferences" from the drop-down menu.

  3. In the System Preferences window, click on "Security & Privacy."

  4. Go to the "Firewall" tab at the top of the Security & Privacy window.

  5. Click on the lock icon in the bottom-left corner of the window to make changes. You'll need to enter your administrator password.

  6. Once the lock is open, click on the "Turn On Firewall" button.

  7. By default, the firewall is set to block all incoming connections. This is the recommended setting for most users, as it provides the highest level of security.

  8. If you need to allow specific apps to receive incoming connections, click on the "Firewall Options..." button.

  9. In the Firewall Options window, you can see a list of apps and their current settings regarding incoming connections. You can customize the access for individual apps by selecting them from the list and choosing "Allow incoming connections," "Block incoming connections," or "Automatically allow signed software to receive incoming connections."

  10. After making any changes, click the "OK" button to apply the settings.

  11. Close the System Preferences window.

That's it! Your macOS firewall is now turned on, protecting your computer from unauthorized incoming network connections. Keep in mind that the firewall primarily focuses on incoming connections, so it won't affect outgoing connections or your ability to browse the internet or use applications. It is a valuable security feature to keep your system safe while connected to the internet.