Network Detection

The simplest wireless monitoring tools simply provide a list of available networks, along with basic information (such as signal strength and channel). They let you quickly detect nearby networks and determine if they are in range or are causing interference.

• The built-in client. All modern operating systems provide built-in support for wireless networking. This typically includes the ability to scan for available networks, allowing the user to choose a network from a list. While virtually all wireless devices are guaranteed to have a simple scanning utility, functionality can vary widely between implementations. These tools are typically only useful for configuring a computer in a home or office setting. They tend to provide little information apart from network names and the available signal to the access point currently in use.

• Netstumbler (www.netstumbler.com). This is the most popular tool for detecting wireless networks using Microsoft Windows. It supports a variety of wireless cards, and is very easy to use. It will detect open and encrypted networks, but cannot detect “closed” wireless networks. It also features a signal/noise meter that plots radio receiver data as a graph over time. It also integrates with a variety of GPS devices, for logging precise location and signal strength information. This makes Netstumbler a handy tool to have for an informal site survey.

• Ministumbler (www.netstumbler.com). From the makers of Netstumbler, Ministumbler provides much of the same functionality as the Windows version, but works on the Pocket PC platform. Ministumbler is handy to run on a handheld PDA with a wireless card for detecting access points in the field.

• Macstumbler (www.macstumbler.com). While not directly related to the Netstumbler, Macstumbler provides much of the same functionality but for the Mac OS X platform. It works with all Apple Airport cards.

• Wellenreiter (www.wellenreiter.net). Wellenreiter is a nice graphical wireless network detector for Linux. It requires Perl and GTK, and supports Prism2, Lucent, and Cisco wireless cards.