Connection State Definition
A connection progresses through a series of states. These states are as follows:
- LISTEN
- Waiting for a connection request from any remote TCP and port.
- SYN-SENT
- Waiting for a matching connection request after sending a connection request.
- SYN-RECEIVED
- Waiting for a confirming connection request acknowledgment after sending and receiving a connection request.
- ESTABLISHED
- An open connection; the normal state for the data transfer phase of the connection.
- FIN-WAIT-1
- Waiting for a connection termination request from the remote TCP, or an acknowledgement of the connection termination request.
- FIN-WAIT-2
- Waiting for a connection termination request from the remote TCP.
- CLOSE-WAIT
- Waiting for a connection termination request from the local user.
- CLOSING
- Waiting for a connection termination request acknowledgment from the remote TCP.
- LAST-ACK
- Waiting for an acknowledgment of the connection termination request previously sent to the remote TCP.