Wireless access points are becoming easier to set up and while most offer certain safety protocols, hackers are still able to gain access. Netstumbler is a program that searches for unauthorized users on a Wireless Local Area Network (WLAN) who are using 802.11b, 802.11a, or 802.11g.
The program is a free tool for the Windows operating system that uses Active Scanning to send out a probe request and report responses. Users must have a compatible wireless card in their computers for Netstumbler to work. Once the program is installed, users can double-click its icon to start the scanning process.
Netstumbler offers two ways to search for unauthorized signals:
Beaconing causes the wireless access points in a particular area to announce their availability. Beaconing is useful because it does not require that the access point have any traffic, but it will not work on access points not configured to receive beaconing packets.
Network sniffing is a passive way to find signals. Once the wireless receiver is turned on it searches, or sniffs, for signals in the air. It is a random method that requires traffic through the access point for discovery.
Netstumbler has not been updated since 2005, so users with current equipment may need to find patches from secondary sources.Learn more about Internet & Networking