AIR SNARE
AirSnare is an intrusion detection system to help you monitor your wireless network.
AirSnare monitors network traffic for unfriendly MAC addresses and alerts you when a MAC address is found that isn't on the friendly list.
AirSnare also monitor DHCP requests from clients

AirSnare is another tool to add to your Wireless Intrusion Detection Toolbox. AirSnare will alert you to unfriendly MAC addresses on your network and will also alert you to DHCP requests taking place. If AirSnare detects an unfriendly MAC address you have the option of tracking the MAC address's access to IP addresses and ports or by launching Ethereal http://www.ethereal.com/ upon a detection.
http://home.comcast.net/~jay.deboer/airsnare/AirSnare.zip

../