Mac OS 10.3 Firewall
Mac OS 10.3 includes firewall features accessible through the Sharing menu in System Preferences. Sonic.net recommends enabling the Mac OS Firewall to help prevent a variety of security and performance problems. Note: There aren't significant differences between these firewall screenshots and the way these options are displayed in OS 10.4.
Categories
Turning on firewall protection
Open System Preferences
System Preferences is available in many locations and is often right on the dock at the bottom of the screen. Displayed here, it is right under the apple menu:
Click Sharing
Once System Preferences is open, click Sharing. It should be located in the Internet & Network sub-heading:
Click Firewall, then click Start
In the Sharing window, click the Firewall tab and then click the button that says Start.
Your computer now has the built-in firewall running.
Advanced
Making Exceptions for Certain Ports
Sometimes it is necessary to make exceptions for certain ports or programs in order to protect your computer, but also have full us of all of your programs. In the main Firewall screen you will see a listing of the most commonly needed exceptions to the firewall. To exclude these port ranges from the firewall, simply click the checkbox next to the desired option (ex: Printer Sharing):
If a desired port or port range is not listed in the defaults, try clicking on the New button to the right. This will bring up a new window that allows you to manually add a port to exclude from the firewall protection:
If you click on the arrow for the Port Name drop-down, you will be presented with some additional defaults that can be added:
If the defaults don't fit the bill, you can manually add a port or range. Simply add the port in the Port Number field, then put a short description in the Description field. In this case, I chose port 22, which is the common SSH port:
Once you click OK, you should see that your port exception has been added to the list and is checked. You should now be able to use that port without any firewall interference. Note: Sometimes it is necessary to reboot the computer before these changes take effect.
More questions? There is also a wealth of knowledge about the OS X Firewall at the Apple Support site.
