4.2 The Apple AirPort Base Station

The AirPort is a tremendously popular access point (so popular, in fact, that there are a number of variations available: AirPort Graphite, AirPort Snow, and Airport Extreme). It looks like a slick, retro-futuristic prop from "War of the Worlds," and is very portable and rugged. While designed for use with the Mac platform, it works very well as a general-purpose access point (and you don't even need a Mac to configure it; see the next section). As I write this, the original Graphite AirPort sells retail for about $140. What does that get you?

• Direct Ethernet bridging

• DHCP / NAT

• 56k dialup modem port

• User-definable ESSID

• Roaming support

• MAC address filtering

• 40-bit WEP encryption

The Snow AirPort introduced an additional Ethernet port and more firewall options, as well as 104-bit WEP and completely redesigned internals. The new AirPort Extreme (about $199) comes equipped with all sorts of goodies , including two Ethernet ports, and most importantly, a draft 802.11g "Extreme" card. For $50 more, they throw in a USB port (for sharing a printer) and an external antenna connector.

All of the APs in the AirPort family have only one radio (an embedded Orinoco Silver card in the Graphite, an AirPort card in the Snow, and an "Extreme" mini-PCI card in the Extreme model). If you are thinking of adding a do-it-yourself antenna to a Graphite or Snow model, you definitely aren't the first. Take a look at the following URLs for details on how to retrofit an antenna onto the Graphite or Snow:

• http://www.vonwentzel.net/ABS/ExtendedGraphite/index.html

• http://www.wwc.edu/~frohro/Airport/Airport.html

• http://www.vonwentzel.net/ABS/ExtendedSnow/index.html

Out of the box, the AirPort will try to get a DHCP lease from a server somewhere on the Ethernet network, and start serving NAT and DHCP on the wireless, with no password. Yes, by simply plugging your new toy into your LAN, you have eliminated all of the hard work that went into setting up your firewall. Anyone within earshot now has unrestricted wireless access to the network you plugged it into!

While this could be handy at a conference or for any other public-access network, the default configurations are probably not what you want. To change them, you'll need configuration software. Thankfully, configuration of the various members of the AirPort family is remarkably similar. For the rest of this chapter, I'll assume that you are working with a classic Graphite AirPort.