Turn on the application firewall in OS X:

  1. Choose System Preferences from the Apple menu.

Apple Menu and System Preferences
  1. Click Security or Security & Privacy.

Security and Privacy Icon
  1. Click the Firewall tab.

Security and Privacy Window
  1. Unlock the pane by clicking the lock in the lower-left corner and enter the administrator username and password.

Lock Icon
  1. Click "Turn On Firewall" or "Start" to enable the firewall.
  2. Click Advanced to customize the firewall configuration.
Article number: 
Last updated: 
August 15, 2017