CEH Introduction to Ethical Hacking Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Send SYN, then receive SYN-ACK, then send ACK

  Why this is correct

  This is the correct order because the TCP three-way handshake starts with the client sending a SYN packet to initiate synchronization, the server responds with SYN-ACK to acknowledge and synchronize, and finally the client sends an ACK to confirm the connection establishment.

• ✗

  Send SYN-ACK, then send SYN, then send ACK

  Why it's wrong here

  Sending a SYN-ACK as the initial packet is fundamentally flawed because a SYN-ACK is a response, not an initiation. It signifies acknowledgment of a received SYN and synchronization request from the server. The TCP three-way handshake must always commence with an unacknowledged SYN packet from the client to propose a connection, making this sequence illogical.

• ✗

  Send SYN, then send ACK, then send SYN-ACK

  Why it's wrong here

  This sequence is incorrect because the server's immediate response to a client's SYN packet must be a SYN-ACK, not merely an ACK. The SYN-ACK serves to acknowledge the client's synchronization request while simultaneously sending its own synchronization request to the client. Sending only an ACK would fail to establish the server's initial sequence number with the client, preventing proper connection setup.

• ✗

  Send ACK, then send SYN, then send SYN-ACK

  Why it's wrong here

  Initiating the TCP handshake with an ACK packet is impossible, as an ACK's purpose is to acknowledge previously received data or a synchronization request. At the very beginning of a connection attempt, there is nothing to acknowledge. The first packet must be a SYN to propose a connection and establish initial sequence numbers, making this sequence logically invalid.

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