1. TCP State Machine (TCP/IP Illustrated vol. 1) W. Richard Stevens
Client transitions
Starting point
Server transitions
CLOSED
Appl: passive open
send: <nothing.
Appl: active open
send: SYN
LISTEN
App: send data
Recv:SYN; send:SYN-ACK
Send:SYN
Recv:RST
Appl: close
SYN_RCVD
Recv: SYN; send:SYN-ACK
simultaneous open
SYN_SENT
Recv:SYN,ACK
Or timeout
Send:ACK
Recv:ACK; send:<nothing.
Appl:
close
Close:
FIN
ESTABLISHED
CLOSE_WAIT
Data transfer state
Appl : close
Send:
FIN
Appl: close
Send:FIN
Recv:ACK
LAST_ACK
Recv:FIN
send: ACK
Simultaneous close
Send:
nothing
passive close
FIN_WAIT_1
CLOSING
Recv: ACK
send:
<nothing>
Recv:FIN,ACK;
send:ACK
Recv: ACK
send: nothing
FIN_WAIT_2
TIME_WAIT
Recv:FIN
send:ACK
2MSL timeout
Active close