NSE 6 – Network Security Specialist — Question 11

Which of the following statements best describe what a SYN cookie does when a SYN packet is received?

Answer options

• A. It replies with a SYN/ACK packet containing a cookie value on the TCP acknowledge field.
• B. It replies with a RST packet if the SYN packet doesn’t contain the right cookie in the sequence field.
• C. It replies with two SYN/ACK packets. One containing the right acknowledge values, and one containing a wrong acknowledge value.
• D. It sends a SYN/ACK with a cookie in the sequence field.

Correct answer: A, D

Explanation

The correct answer, A, accurately describes that a SYN cookie is used to respond to a SYN packet with a SYN/ACK packet that includes a cookie value in the TCP acknowledge field. Option D, although it involves a SYN/ACK, incorrectly states the location of the cookie, which is actually in the TCP acknowledge field, not the sequence field. Options B and C do not accurately represent the function of SYN cookies in handling SYN packets.