by , 7:30 AM EDT, April 14th, 2006

Your Mac may be inherently safer on the Internet than its Windows counterparts, but that doesn't mean you don't need to pay attention to your Mac's online safety. Luckily, you don't even have to buy any extra software because Mac OS X comes with an industrial strength firewall ready to keep hackers out of your computer. Your Mac shipped with its firewall deactivated by default, but it's easy to turn on.

• Choose Apple menu > System Preferences.
• Click the Sharing Preference Pane.
• Click the Firewall tab.
• Click the Start button to turn your firewall on. If the button says Stop, your firewall is already running.

Use Tiger's firewall to protect your Mac from hackers.

Once your Mac's firewall is running, no one without authorization should be able to get at your files wither through your network or through the Internet. In essence, a firewall is like a wall that surrounds your Mac, protecting it from any network or Internet-based attacks.

You can also make your Mac invisible to other computers on the Internet. Here's how:

• While you are still in the Sharing Preference Pane's Firewall tab, click the Advanced button.
• Check Block UDP Traffic.
• Check Enable Stealth Mode.
• Click the OK button.

Enabling Stealth Mode makes your Mac invisible on the Internet.

Protecting your Mac from unwanted hacking attempts is what a firewall is good at, but it can't keep you safe from virus threats. Although viruses aren't a big threat today, you'll need to install an antivirus application if you want any protection from potential virus, worm, and trojan horse threats. We'll take a look at antivirus software in another Quick Tip.

if you have ideas for Mac related tips that you think other TMO readers might find helpful.