9.3. The FirewallIf you have a broadband, always-on connection, you're connected to the Internet 24 hours a day. It's theoretically possiblealthough very unlikelyfor some cretin to use automated hacking software to take control of your machine. If your Mac is connected to a router as described on Section 5.2, its firewall circuitry is probably protecting you. If not, Mac OS X's firewall software can put up a simpler, but effective, barrier .
To turn it on, open the Sharing pane of System Preferences. Click the Firewall tab (Figure 9-4), and then click Start. That's all there is to it: You're protected. Note: If you're using Mac OS X's Internet connection-sharing feature, turn on the firewall only for the first Macthe one that's the gateway to the Internet. Leave the firewall turned off on all the Macs "downstream" from it.And if you have some program that's raising trouble because it can't get through your firewall (an online game, for example), head back to the Sharing pane and click Add. In the dialog box that appears, choose Other from the Port Name menu and fill in the lower fields as instructed in the program's help files. You've now allowed that program's traffic to pass unimpeded through your Mac's firewall. |