PC Security Feature: Configure your Mac Firewall

Protect your computer from outside intrusion

Whether you make light or heavy use of the Internet is irrelevant. The simple fact that you have an active network connection means that you’re sharing data with others. Unless you protect this connection you leave yourself open to hackers, who may provide software that shares your financial details - this is particularly the case when using PayPal or eBay.

To protect against this OS X includes a firewall. For a firewall to be effective you need to decide which applications will and will not be allowed to communicate with another computer. Mail, Safari and iTunes should be given a relative free reign as you’re dealing with only one server, whereas P2P applications such as LimeWire should have much tighter restrictions.

For a firewall built into an operating system, that supplied with OS X offers somewhat more versatility than the Windows XP equivalent; but it will always work best when backed up with an effective anti-virus program. Norton AntiVirus 10.0 (www.symantec.com, $49.99) is one of the longest established, and being backed by one of the largest antivirus companies in the world is likely to be the quickest updated against any OS X viral infections.

STEP # 1 | Disable unwanted services

From the Apple menu select ‘System Preferences’ then ‘Sharing’. This opens the ‘Sharing Preferences’, divided into three categories – ‘Services’, ‘Firewall’ and ‘Internet’.

The ‘Services’ tab allows you to state the ways in which other computer users can access the resources you have available. From sharing a personal folder to accessing files on a Windows XP computer; down to FTP access and sharing your printer you’ll need to have a tick in the ‘On’ column if you want that service enabled.


STEP # 2 | Activate the Firewall

Let’s move to the Firewall section. If you wish to protect your computer against unauthorised access the Firewall will need to be switched on. If it’s not, click the ‘Start’ button at the top of this window.

To allow one of the listed services to communicate across the Internet, click within the tick box to activate it. Note that if you’ve not enabled a service within the ‘Services’ window, it will not be available to configure within the ‘Firewall’ window. Select one of the active services then click ‘Edit’.


STEP # 3 | Edit options

The ‘Edit’ window allows you to specify the port on which you’d like to receive networking traffic. Essentially this is the gateway through which an application can talk to another computer via your network connection, until such point as you decide to close the gate.

If more than one application attempts to claim the same port, you’ll find that they’ll not run properly. To resolve this you may find an option within the program in question. Contact the supplier for further details.


STEP # 4 | Advanced Options

With a click of the ‘Advanced’ button the OS X Firewall sneak security options become available. Here you can block UDP traffic (network messages), keep a log of the Firewall activity (who is trying to communicate with you, and which applications are trying to communicate with which servers) and enable the Stealth Mode (essentially hiding your computer).

Individually they provide an extra tool in the arsenal of security applications that will safeguard the long-term security of your computer.