An introduction to the Kismet packet sniffer

Kismet is a wireless "detector, sniffer, and intrusion detection system," and one of the growing list of essential open source tools for computer network security professionals. Kismet runs on any POSIX-compliant platform, including Windows, Mac OS X, and BSD, but Linux is the preferred platform because it has more unencumbered RFMON-capable drivers than any of the others.

Monitor mode ability is critical to fully utilizing Kismet, because it allows Kismet to examine all the packets it can hear, not just those of whatever access point (AP) -- if any -- you are currently associated with. Almost as important to police, intelligence agencies, and black hat hackers is the fact that it allows Kismet to work passively, intercepting and collecting packets without leaving any fingerprints of its own behind.

The point is that if you want to investigate Kismet fully, the first step is to ensure that you have a driver taht supports RFMON -- monitor mode -- for your wireless network interface card (NIC). Check the Kismet links page for information on the drivers available for your brand and model NIC.