Wireless Hacks

Apple Software Base Station

Use an OS X machine with an AirPort card as a true access point.

Mac OS 9 had a handy AirPort feature called “Software Base Station.” It allowed any Mac with an AirPort card and an Ethernet (or dialup) connection to act like a hardware access point, sharing its Internet connection over the wireless. The early versions of OS X were noticeably lacking this handy feature, but it has been restored in OS X 10.2.

To begin, you need to establish a connection to the Internet over something other than wireless (Ethernet is ideal). You might think that to start a new wireless network, you could simply click on the AirPort icon and select Create Network, but this will make an IBSS (peer-to-peer) network. In order to turn your Mac into a true access point, you need to go to System Preferences → Sharing, and click on the Internet tab, shown in Figure 4-2.

Figure 4-2. Enable Software Base Station in the Sharing Control Panel.

Check the top box (Share your Internet connection with AirPort-equipped computers), but before clicking the Start button, you probably want to set up your wireless parameters. Click the AirPort Options... button, and you should see a drop-down menu like that shown in Figure 4-3.

Figure 4-3. Set up your radio parameters under AirPort Options.

Specify a network name and channel, and turn on WEP [Hack #86] if you need it. Click OK, then click the Start button. Close the control panel, and your AirPort icon should change to include an arrow (Figure 4-4). This means that your AirPort is now operating as a real access point.

Figure 4-4. Software Base Station engaged!

To turn off sharing and return to normal AirPort operations, go back to the Sharing control panel (or just click Open Internet Sharing... from the AirPort menu bar) and click the Stop button. As long as you have Internet sharing enabled, anyone in range of your Mac will see it as a normal access point, and can access the Internet just as if it were a hardware AP. I’m not sure why Apple made this feature a bit obscure to enable, but it can come in handy in a pinch when you need an AP in a hurry.