6.1.3 - TCP Handshake and Teardown

Flashcards covering the TCP handshake and teardown process.

First step of TCP three-way handshake

Client sends a SYN segment with a random sequence number and enters SYN-SENT state.

Second step of TCP three-way handshake

Server responds with SYN/ACK, containing its own random sequence number, and enters SYN-RECEIVED state.

Third step of TCP three-way handshake

Client responds with an ACK segment and assumes the connection is ESTABLISHED.

First step of TCP connection teardown

Client sends a FIN segment and enters FIN-WAIT1 state.

Second step of TCP connection teardown

Server responds with an ACK segment and enters CLOSE-WAIT state.

Third step of TCP connection teardown

Client receives the ACK segment and enters FIN-WAIT2 state.

Fourth step of TCP connection teardown

Server sends its own FIN segment to the client and goes to the LAST-ACK state.

Fifth step of TCP connection teardown

Client responds with an ACK and enters the TIME-WAIT state; after a defined period, the client closes its connection.

TCP reliability

The sending machine expects regular acknowledgments for segments it sends and, if a period elapses without an acknowledgment, it assumes the information did not arrive and automatically resends it

TCP reset (RST) segment

A host can also end a session abruptly using a reset (RST) segment.