Understanding Cisco Cybersecurity Fundamentals (SECFND, legacy) — Question 44

Which one of the following options describes the protocol and port that is used by DNS?

Answer options

• A. TCP 53
• B. UDP 53
• C. UDP 53 and TCP 53
• D. any registered port

Correct answer: C

Explanation

The correct answer is C because DNS can operate over both UDP and TCP, using port 53 for both protocols. Option A and B are incorrect as they only mention one protocol each, while option D is misleading since DNS specifically uses port 53, not just any registered port.