Wireless Tools for Windows and Linux
With the increased interest in Linux in recent years, many computer users today ask themselves, “What hardware should I purchase that I can use with Windows and Linux?” and “Which operating system will best suit my purposes?” Sometimes, determining hardware compatibility with different operating systems can be difficult, especially for wireless products. For those unfamiliar with Linux, making such a decision can be a daunting task that is further complicated by the large number of companies selling wireless cards. Fortunately, there are far fewer companies producing chipsets for use in these wireless cards, thus simplifying the process some because the drivers are based on chipset, not card manufacturer. Currently, the most common chipsets are Atheros, Cisco, Orinocco, Intersil Prism and Intel.
Providing a list of chipsets based on the card manufacturer is nearly impossible because most manufacturers do not provide this information openly and sometimes change chipsets for a wireless card mid-model. The best way to determine which chipset a card uses is to search the Internet.
Of course, due to the number of Windows machines in use around the world, all of these cards have drivers available for Windows XP and often Windows 2000. Simply install the latest drivers from the manufacturer and you should be ready to go. The Windows drivers have a few problems when compared with the Linux drivers, most importantly is that most, if not all, of the Windows wireless drivers do not support all available features, such as promiscuous mode, which limits the functionality on Windows. These limitations have lead to a smaller number of wireless utilities being available for Windows. Of the wireless utilities available for Windows, perhaps the most useful is a program called NetStumbler, which can be found at http://www.netstumbler.com.
NetStumbler is a program that actively searches for wireless access points within range. In order to find the access points, NetStumbler relies upon the Service Set Identifier (SSID) being broadcast from the access point. NetStumbler accomplishes this by actively probing for access points. Unfortunately, this method also makes the program more prone to being overwhelmed by fake access points set to deter those searching for APs in the area. In addition, if an access point has broadcast disabled, then the access point is virtually invisible to NetStumbler. NetStumbler will also work with some models of Global Positioning Systems (GPS) to associate coordinates with your location when the access point was detected. All of the information that NetStumbler gathers can then be saved in a log file for future use. To work with these log files, a wide range of utilities have been created, many of which have links on the NetStumbler site.
|Not fully open source; the HAL is only available as a binary file. Some cards support 802.11a, b and g.|
|Latest version requires a fairly new kernel version.|
|Provided by Cisco but no official support.|
|Does not use standard Linux tools for configuring wireless cards; requires its own utilities, available from the same site.|
|Also provides software to allow Linux to function as a wireless access point. Uses standard Linux wireless tools.|
|Both of these are used with Windows drivers, but functionality is limited to that with Windows.|
For Linux, configuring the wireless card is a bit more complicated than on Windows. First, you must determine the chipset of the card. To assist in determining the chipset, a slightly outdated list of cards and chipsets can be found at http://www.linux-wlan.org/docs/wlan_adapters.html.gz. Otherwise, a search with any of the search engines should provide some useful information.
Once the chipset is determined, the next step is to download and install the drivers. Although many wireless cards are supported in the most recent kernels (2.6.x), separate drivers provide better features and are more easily updated as newer versions become available. For those cards with multiple choices of drivers in the table below, you should choose a driver based the functionality required. The following table provides some information regarding the available choices. Although this table is not an exhaustive list of drivers, it does provide some suggestions to get started.
Details on how to install each of these drivers can be found at the Web sites listed, with additional information found by searching the Internet. One of the best resources for such information is http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/. This Web site provides useful information along with a number of links to other sites. Once the driver is installed, a wide range of tools are available for working with wireless cards on Linux.
One way to avoid the trouble of configuring wireless cards under Linux is to use a Live-CD distribution of Linux that comes preconfigured with the necessary drivers and software. Many such distributions exist, but some of the more popular versions are Knoppix-STD (http://www.knoppix-std.org/) and Auditor (