Linux Unwired

Chapter 2. Wi-Fi on Your Linux Box

Wireless support on Linux has come a long way. With modern Linux distributions, you may not need to recompile your kernel to receive support for your Wi-Fi card. You probably won’t need to install driver software or even touch a command line. However, this isn’t always the case, especially as new cards come on the market, so you should still have a good understanding of how Wi-Fi works under Linux. This chapter starts out with an explanation of what you need to do with some common distributions and a common radio card, and then gets into the details you need to know to take things a little further, including radio chipsets, drivers, kernel compilation, the PCMCIA subsystem, and the Linux wireless tools.

Quick Start

If you haven’t purchased a Wi-Fi card yet, and are happy with 802.11b (about 5.5 Mbps real-world speed versus about 20 for 802.11a or g), pick up either a Lucent/Agere/Avaya/Proxim Orinoco Silver or Orinoco Gold (see Section 2.2.1.2 later in this chapter). If you’ve purchased a different card, it may work out of the box with Linux. But if it doesn’t, the rest of this chapter describes chipsets and drivers in enough detail for you to find your way. Unfortunately, the orinoco_cs driver does not support monitor mode, which passive monitoring tools such as Kismet require. See Chapter 3 for information on monitor mode and available patches for orinoco_cs. If you want to use monitor mode with an unpatched driver, we suggest that you use a Prism ...