Real screenshot · MacBook Neo, macOS 27.0.1In short
Open System Settings, click Network, then Firewall, and turn on the Firewall switch. Confirm with Touch ID or your password. Click Options… afterwards if you want stricter rules.
The firewall stops other computers on the network from connecting to your Mac unless you allow it, which is worth having on Wi-Fi in cafes, hotels or airports.
4 of 5 steps show a real screenshot from our MacBook Neo.
Steps
- 1
Open System Settings
Click the Apple menu in the top left corner, then click System Settings….
- 2
Click Network, then Firewall
Click Network in the sidebar, then click the Firewall row.
On our MacBook Neo, Firewall is the second row, under Wi-Fi, and reads Inactive while it is off.
- 3
Turn on the Firewall switch
Click the switch next to Firewall.
On our MacBook Neo, the page says: "This computer's firewall is currently turned off. All incoming connections to this computer are allowed."
- 4
Confirm with Touch ID or your password
On our MacBook Neo, the prompt reads "Network is trying to unlock system settings."
Use Touch ID, or click Use Password… and enter your password.
- 5
Click Options… for more control (optional)
Apple says the Options button is disabled until the firewall is on; on our MacBook Neo, Options… is grey while the switch is off.
Apple says you can allow or block incoming connections for individual apps there. Most people can leave the settings as they are.
If you do not see this option
- Options… is grey Apple says the Options button is disabled until you turn on the firewall. On our MacBook Neo it is grey while the switch is off. Sources: Block connections to your Mac with a firewall, Change Firewall settings on Mac, Block connections to your Mac with a firewall (macOS Monterey 12)
- Firewall reads Inactive That is how the Network page on our MacBook Neo shows a firewall that is off. Click the row to reach the switch.
- Your Mac has System Preferences Apple's guide for macOS Monterey 12 says to open System Preferences, click Security & Privacy, then Firewall, and click Turn On Firewall. If the lock at the bottom left is locked, click it first. Sources: Block connections to your Mac with a firewall, Change Firewall settings on Mac, Block connections to your Mac with a firewall (macOS Monterey 12)
If this does not work
- The switch asks for Touch ID or a password Turning on the firewall needs your approval. On our MacBook Neo, the prompt offers Use Password… and Cancel; click Use Password… if you cannot use Touch ID.
- A sharing service still accepts connections Apple says turning on a sharing service such as file sharing opens a port through the firewall. Turn the service off in Sharing settings to stop it.
- An app stops working after you block it Apple says blocking an app can affect it or other software that depends on it. Set it back to allow incoming connections in Options.
- An app not in the list still connects Apple says some system apps and signed apps have access without being listed. Add them to the list to block them.
Good to know
Apple says Block all incoming connections prevents incoming connections to all apps and services that are not essential. Use it on networks you do not trust.
Apple says Enable stealth mode makes the Mac ignore test requests such as ping, so it is harder to find on a network.
Apple says the two settings that begin with Automatically allow let Apple's own software and signed apps receive connections without asking you each time.
The firewall checks only incoming connections. It does not replace updates or a disk that is locked with FileVault.
macOS 27 compared with macOS 26: We rewrote steps 1, 2, 3, 4 and 5 to match the macOS 27 screens. The macOS 26 page keeps the steps and screenshots as they were.
Version history: the macOS 26 version of this guide, with its own screenshots.
About this guide
- Device
- Mac
- Shown on
- macOS 27.0.1 (MacBook Neo)
- App
- System Settings
- Real screenshots
- 4 of 5 steps
- Checked
- October 2026
- Sources
- 3 official, linked below
Sources
Links checked October 2026. Menus and features can change with updates.Did this guide work for you?
Sorry about that. What happened?