Mac OS X 10.4 Help
Using a firewall to protect your computer
Mac OS X includes firewall software you can use to block unwanted network communication with your computer. Using a firewall protects your computer from users on other networks or the Internet.
In order to use Mac OS X services, such as personal file sharing, Windows sharing, or FTP access, you need to open ports in the firewall to allow traffic for that service to and from your computer. When you select a service in the Services pane of Sharing preferences, it is automatically selected in the Firewall pane, and the port is opened.
To prevent that service while the firewall is on, turn off the service in the Services pane.
To turn on firewall protection on your computer:
- Open System Preferences and click Sharing.
- Click Firewall, and then click Start.
To block incoming traffic on ports used by one of the sharing services, disable that service in the Services pane.
You can't edit the firewall ports used by built-in services. They are enabled and disabled automatically when you turn the corresponding service on or off in the Services pane.
If you use iChat Bonjour, iTunes Music Sharing, or iPhoto Bonjour Sharing, make sure to allow those services in and out of your firewall. Turn on their services on the Firewall pane of Sharing preferences.