Speaking of creating an ad-hoc (or computer-to-computer) network, this is something you can also do via the Wi-Fi menu. Click on this menu, and you'll see a Create Network command. This command allows you to turn your Mac into a wireless hotspot, which you can share with others. Back in the days when most hotels had only wired ethernet Internet available, you'd use this so you could connect other nearby wireless devices to the hotel network (without having to pay for an additional connection or because your other devices didn't support ethernet).
Creating an ad-hoc network is still a good solution in that increasingly rare situation, but there are other reasons to do it, too: for instance, when you want to create a secure network that only those who know the network's password can log in to.
To create a computer-to-computer network, just choose the Create Network command and, in the sheet that appears, create a network name ('Super Secret Network', for example) and choose a channel to broadcast over. (Channel 11 is the default, but if there's a lot of wireless traffic where you are--which can degrade the signal--choose another channel such as 1 or 6.) And if you want a secure network, click the Security pop-up menu and choose 40-bit or 128-bit WEP (Wired Equivalent Privacy)--128-bit is more secure. If you choose either WEP setting, you must enter and confirm a password--exactly five characters for 40-bit WEP and 13 characters for 128-bit WEP.
More? Okay. Some nearby Wi-Fi networks don't appear in the Wi-Fi menu because they've been set up as private networks--networks you can access only if you know their name and password. If you're aware of such a network (because the boss sidled up to you and hissed "Not only have you earned the key to the executive washroom, but you can now use our private network. Its name is 'Perk' and the password is 'ent1tled.'") just choose Join Other Network from the Wi-Fi menu and in the window that appears enter the network name, choose the kind of security the network uses, enter the network's password, and click Join.
Where this leads
Configuring a Mac to join a network is a necessary but unenthralling chore. But now that you have established a network, the good stuff can begin: You can now share printers and scanners, swap files, and remotely control another Mac on your network. We'll look at these tasks next week.
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