To build tcpdump under Windows, you need: - version 6 (or higher) of Microsoft Visual Studio or the Cygnus gnu C compiler. - The November 2001 (or later) edition of Microsoft Platform Software Development Kit (SDK), that contains some necessary includes for IPv6 support. You can download it from http://www.microsoft.com/sdk - the WinPcap source code, that includes libpcap for win32. Download it from http://winpcap.polito.it or download libpcap sources from http://www.tcpdump.org and follow the instructions in the README.Win32 file. First, extract tcpdump and WinPcap in the same folder, and build WinPcap. The Visual Studio project and the cygwin makefile are in the Win32\prj folder. From Visual Studio, open windump.dsw and build the program. The release version of the WinDump.exe executable file will be created in the windump\win32\prj\release directory . The debug version will be generated in windump\win32\prj\debug. From cygnus, go to windump\win32\prj\ and type "make". WinDump.exe will be created in the same directory.