tcpdump is a common packet sniffer that allows the user to intercept and display TCP/IP and other packets being transmitted or received over a network to which the computer is attached. It was originally written by several people working in the Lawrence Berkeley Laboratory; now distributed under a permissive free software licence, and works on most Unix-like operating systems. There are also a few ports of tcpdump for Windows.
All existing packet sniffers can export the packets in tcpdump format:
In addition, EWSA suppoorts the 'native' file format produced by
CommView for Wi-Fi software.
The captured data should contain the full authenication handshake from a real client and the access point.