A socket can be in various states (bound to an address/port, unbound, listening, idle, etc.)
Other than ESTABLISHED, here are some other possible states that netstat can output:
Quote:
BOUND Bound, ready to connect or listen.
UNBOUND Not waiting for anything,
CLOSED Closed. The socket is not being used.
CLOSING Closed, then remote shutdown; awaiting acknowledgment.
CLOSE_WAIT Remote shutdown; waiting for the socket to close.
FIN_WAIT_1 Socket closed; shutting down connection.
FIN_WAIT_2 Socket closed; waiting for shutdown from remote.
IDLE Idle, opened but not bound.
LAST_ACK Remote shutdown, then closed; awaiting acknowledgment.
LISTEN Listening for incoming connections.
SYN_RECEIVED Initial synchronization of the connection under way.
SYN_SENT Actively trying to establish connection.
TIME_WAIT Wait after close for remote shutdown retransmission.
10-06-2012
