nerdexam
Cisco

200-301 · Question #836

Which two TCP messages use a 32-bit number as part of the initial TCP handshake? (Choose two.)

The correct answer is A. SYN E. ACK. During the initial TCP handshake, the SYN segment carries the client's Initial Sequence Number, and the final ACK segment carries the acknowledgment number for the server's sequence number, both of which are 32-bit values.

Submitted by takeshi77· Mar 5, 2026Network Fundamentals

Question

Which two TCP messages use a 32-bit number as part of the initial TCP handshake? (Choose two.)

Options

  • ASYN
  • BRST
  • CSYN-ACK
  • DFIN
  • EACK

How the community answered

(29 responses)
  • A
    93% (27)
  • B
    3% (1)
  • C
    3% (1)

Why each option

During the initial TCP handshake, the SYN segment carries the client's Initial Sequence Number, and the final ACK segment carries the acknowledgment number for the server's sequence number, both of which are 32-bit values.

ASYNCorrect

The SYN (synchronize) segment initiates the TCP handshake and contains the client's 32-bit initial sequence number (ISN).

BRST

RST (reset) is used to immediately terminate a TCP connection and is not part of the initial handshake.

CSYN-ACK

While the SYN-ACK segment also uses 32-bit sequence and acknowledgment numbers, the question specifically seeks two distinct messages that utilize a 32-bit number in the handshake.

DFIN

FIN (finish) is used to gracefully terminate a TCP connection and is not part of the initial handshake.

EACKCorrect

The final ACK (acknowledgment) segment in the three-way handshake acknowledges the server's initial sequence number, carrying a 32-bit acknowledgment number.

Concept tested: TCP 3-way handshake and segment fields

Source: https://learn.microsoft.com/en-us/windows/win32/winsock/tcp-connection-setup-and-teardown

Topics

#TCP handshake#TCP sequence numbers#TCP acknowledgment numbers

Community Discussion

No community discussion yet for this question.

Full 200-301 Practice