An explanation of common TCP states.
SYN_SEND Indicates active open.
SYN_RECEIVED Server just received SYN from the client.
ESTABLISHED Client received server's SYN and session is
LISTEN Server is ready to accept connection.
NOTE: See documentation for listen() socket call. TCP
sockets in listening state are not shown - this is a limitation of NETSTAT. For
additional information, please see the following article in the Microsoft
134404 NETSTAT.EXE Does Not Show TCP Listen Sockets
FIN_WAIT_1 Indicates active close.
TIMED_WAIT Client enters this state after active close.
CLOSE_WAIT Indicates passive close. Server just received
first FIN from a client.
FIN_WAIT_2 Client just received acknowledgment of its first
FIN from the server.
LAST_ACK Server is in this state when it sends its own FIN.
CLOSED Server received ACK from client and connection is