Network Discovery Using NetStumbler

Find all available wireless networks with this infamous monitoring tool.

Once you’ve tried using the wireless client software included with any of the major operating systems, you’ll quickly realize the major shortcomings of these utilities. Most tools don’t give a detailed measurement of signal strength and won’t even indicate when multiple networks are using the same channel.

NetStumbler ( is an excellent (and free) utility that will give you a great deal of detail about all of the wireless networks in range, including their ESSID, whether they use WEP, the channels they use, and more. As of this writing, the current version is 0.30, and the author is working on Version 0.4. Installation is easy and quick, and for everything that NetStumbler does, the software package is remarkably small.

NetStumbler does not support all wireless network cards. You’ll want to check the README before installing to make sure you’ve got a compatible wireless card. Supported cards include all cards using the Hermes chipset (Lucent/Orinoco/Avaya/Agere/Proxim cards). As of Version 0.30, the software also supports native NDIS 5.1 drivers in Windows XP, allowing it to support Cisco Aironet and some Prism-based cards.

When you launch NetStumbler for the first time, you’re going to want to set some options. Click on View and select Options. You’ll see the Options dialog as shown in Figure 3-9.

Figure 3-9. NetStumbler Options.

There are a couple ...

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