WiFi Setup Guide Macos X

All currently shipping Macs use the Mac OS X operating system, and all of them include built-in Wi-Fi antennas and a card slot for accepting either an AirPort 802.11b card or AirPort Extreme 802.11g card. The latest models use the AirPort Extreme card, while iBooks and the 15.2-inch PowerBook, also known as the Titanium, accept the standard AirPort card. The two cards are not interchangeable, so be sure to buy the appropriate card for your Mac model.

If your Mac shipped before January 2003, you can choose an AirPort (802.11b-only) card, or you can buy a third-party USB or PC card adapter -- the only way your older Mac can support 802.11g. If you do, though, be sure that the adapter you buy uses the same Broadcomm chip that powers the AirPort Extreme card. With the latest version of Mac OS X installed, you'll be able to use built-in drivers with the third-party card.

In this section, we describe basic wireless setup under OS X, special situations for older Macs, and ad-hoc networking. First, install an AirPort card according to the directions that came with your Mac.

Connecting to a Wireless Network with AirPort and OS X If you're using Apple drivers to power your Apple or third-party wireless adapter, getting connected to an available network is extremely simple. You will use the same procedure whether you're using AirPort or airport Extreme equipment. Note that you will need an administrator account on the Mac. Follow these steps:

  1. With the AirPort or compatible adapter installed, start up your Mac and open the System Preferences (Apple Menu > System Preferences).
  2. Click the Network icon to view networking options.
  3. Choose AirPort from the Show menu to view setting for your wireless connection. If you don't see AirPort, choose Network Port Configuration instead, click the checkbox next to AirPort and then click Apply Now to activate the new configuration.
  4. With the AirPort item selected from the Show menu, click the AirPort tab.
  5. Choose how you want to connect to a wireless network: Join the network with the best signal or Join most recently used available networks make it possible for you to get onto a network automatically, without returning to the Network window again, once your settings have been established for the first time. If you activate the Join a specific network radio button, you'll see a list of available networks when you pull down the arrow next to the Network field.
  6. If you choose to join a specific network, type your password, if the network is password-protected. If you have chosen one of the other options, you will be prompted for a password.
  7. Unless you disable the feature using the checkbox, AirPort menu options will appear in the menu bar, once you've applied your changes. This is a handy timesaver when you pop open your PowerBook or iBook in a new location.
  8. By default, Mac OS X assumes that your will obtain an IP address from a DHCP server on the wireless network. If you have been assigned a static IP address, or have another special connection situation, click on the TCP/IP tab in the Network window. Make changes to your configuration and click Apply Now to confirm them.
  9. If you need to enable AppleTalk -- to communicate with an AppleTalk-only printer, for example -- click the AppleTalk tab and then the Make AppleTalk Active checkbox. If you don't need AppleTalk, leave it disabled. Note that if you are connected to both a wireless and a wired network, AppleTalk can only be enabled for one of these connections. In most cases, that means you will use it in the wired network.

Special Situations

Two kinds of users will not be able to use Apple's AirPort drivers to make a wireless connection: those whose Macs don't have AirPort slots, and those who have chosen to use a third-party device that they may have on hand.

A few vendors, including Asante and MacWireless, produce PC cards that are compatible with many Apple PowerBooks. These vendors include their own software drivers. USB adapters are also available, though they're difficult to find. Older iMacs are the target audience for these devices.

MacWireless and IOXperts also sell driver software packages that claim compatibility with most 802.11b PC cards, though not with PCI and USB products. Finally, Proxim's Orinoco PC cards are unique options, in that they can be used both with Apple's AirPort drivers and with software the company itself provides.

Creating an Ad-hoc Network

You can build a network between two wireless computers. They need not be using the same operating system. To create such a network, always start with the computer that will host the network. If you plan to give other members of the network access to the Internet through the wireless link, choose a computer that has a connection to the Internet as your network host.

  1. From the AirPort menu on the menu bar, choose Create network. If you haven't already enabled the AirPort menu in the Network System Preferences pane, do that first.
  2. Name your network in the Computer-to-Computer window.
  3. Leave the Channel setting alone unless there are a number of other wireless networks nearby. It's best that wireless networks by set to operate on channels as distant from other nearby networks as possible to minimize radio interference.
  4. To enable WEP for your network, click the Show Options button.
  5. Click Enable Encryption (using WEP) to activate the options.
  6. Type a password for your network, and then retype it.
  7. Click OK to complete the process.
  8. Choose Apple menu > System Preferences and click the Network panel.
  9. Select AirPort from the Show menu.

In order for wireless computers on a network to communicate, their IP addresses must be on the same subnet. An IP subnet is a range of numbers that create boundaries for your local network. When your network is managed by a wireless gateway, the gateway point's DHCP server typically hands out addresses within the same subnet to all members of the network.

Since your ad-hoc network does not have a server to provide addresses, you will need to create a static IP address for each device on the network. Using a private IP subnet, you can assign addresses that are valid only within the local network. For example, start by assigning the computer that hosts your network an IP address of, and give each client computer an address in that range (i.e. through

On each networked computer, use a subnet mask of and be sure that the gateway address field of each is empty. Connect one or more computers to your new ad-hoc network, give them IP addresses.