How to block Mac App Connections

Configuring the application firewall in OS X v10.6 and later

Use these steps to enable the application firewall:

1. Choose System Preferences from the Apple menu.
2. Click Security or Security & Privacy.
3. Click the Firewall tab.
4. Unlock the pane by clicking the lock in the lower-left corner and enter the administrator username and password.
5. Click "Turn On Firewall" or "Start" to enable the firewall.
6. Click Advanced to customize the firewall configuration.

Configuring the Application Firewall in Mac OS X v10.5

Make sure you have updated to Mac OS X v10.5.1 or later. Then, use these steps to enable the application firewall:

1. Choose System Preferences from the Apple menu.
2. Click Security.
3. Click the Firewall tab.
4. Choose what mode you would like the firewall to use.