Office of Information Technology

Enable the Mac OS X Firewall


A firewall, in conjunction with software updates and virus protection, will help protect you from hackers and malicious software that may attempt to access your computer over the network or Internet.

Enabling the Firewall in OS X v.10.7 Lion

  1. Open SYSTEM PREFERENCES from the Dock. (It can also be found under the APPLE MENU.) 
  2. Then, click on the SECURITY & PRIVACY icon. 
  3. Click on the FIREWALL tab. 
  4. Then, click on the START button to enable the firewall if it is not already enabled.
  5. Close the Security & Privacy window to save changes. 

Enabling the Firewall in OS X v.10.6 Snow Leopard

  1. Open SYSTEM PREFERENCES from the Dock. (It can also be found under the APPLE MENU.) 
  2. Then, click on the SECURITY icon. 
  3. Click on the FIREWALL tab. 
  4. Then, click on the START button to enable the firewall if it is not already enabled.
  5. Close the Security window to save changes. 

 

Enabling the Firewall in OS X v.10.5 Leopard

  1. Open SYSTEM PREFERENCES from the Dock. (It can also be found under the APPLE MENU.) 
  2. Then, click on the SECURITY icon. 
  3. Click on the FIREWALL tab. 
  4. Then, select the ALLOW ONLY ESSENTIAL SERVICES radio button.

    osx_firewall

  5. Close the Security window to save changes. 
  6. Rendezvous and iTunes sharing will be turned on by default, if you have iChat and iTunes set up to share. We do not recommend enabling any other ports.