Which option lists the correct sequence of a TCP three-way handshake?

The correct answer is B. SYN, SYN-ACK, ACK. Option B is correct because the TCP three-way handshake follows a strict sequence: the client sends SYN (synchronize) to initiate the connection, the server responds with SYN-ACK (synchronize-acknowledge) to confirm receipt and signal its own readiness, and finally the client…

Network Security Fundamentals

Question

Which option lists the correct sequence of a TCP three-way handshake?

Options

ASYN, ACK, SYN
BSYN, SYN-ACK, ACK
CSYN, ACK, FIN
DSYN, SYN-ACK, FIN

How the community answered

(21 responses)

A
5% (1)
B
90% (19)
D
5% (1)

Explanation

Option B is correct because the TCP three-way handshake follows a strict sequence: the client sends SYN (synchronize) to initiate the connection, the server responds with SYN-ACK (synchronize-acknowledge) to confirm receipt and signal its own readiness, and finally the client sends ACK (acknowledge) to complete the connection establishment.

A (SYN, ACK, FIN) is wrong because a bare ACK cannot initiate the server's side of the synchronization - the server must send SYN-ACK, not just ACK.
C (SYN, ACK, FIN) is wrong because FIN is used to terminate a connection (the four-way teardown), not establish one.
D (SYN, SYN-ACK, FIN) mixes connection setup with teardown - the final step must be ACK, not FIN.

Memory tip: Think of it as a phone call - "Can you hear me?" (SYN) → "Yes, and can you hear me?" (SYN-ACK) → "Yes!" (ACK). The phrase "Synchronize, Synchronize-Acknowledge, Acknowledge" spells out the logic of each step.

Topics

#TCP handshake#Connection establishment#Network protocols#TCP three-way

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