Start the Built-in Firewall in Mac OS X (v. 10.2 or higher)
1. Pull down the Apple icon in the top left corner of your Desktop
2. Select System Preferences from the menu.
3. Under the category Internet & Network click on the Sharing icon.
4. Make sure the Firewall tab is selected.
5. Click the Start button to enable the built-in firewall in your operating system.
|To pause, click the video once. Click again to play. [about this video]|