Tcp
From wikinotes
TCP states
TCP states can be seen in netstat, and they are a crucial part of diagnosing issues with your programs.
http://benohead.com/tcp-about-fin_wait_2-time_wait-and-close_wait/ Very good tutorial on diagnosing issues with TCP http://stackoverflow.com/questions/4501877/python-multiprocessing-and-sockets-not-being-closed Python Multiprocessing socket-server changing pids