Understanding Cisco Cybersecurity Fundamentals (SECFND, legacy) — Question 101

What is a DNS tunnel?

Answer options

• A. A type of VPN tunnel that uses DNS.
• B. A type of MPLS deployment that uses DNS.
• C. DNS was not created for tunneling, but a few tools have used it to encapsulate data in the payload of DNS packets.
• D. An encryption tunneling protocol that uses DNS’s UDP port 53.

Correct answer: B

Explanation

The correct answer is B, as it describes a type of MPLS deployment involving DNS. Options A and D incorrectly relate DNS tunnels to VPNs and encryption protocols, respectively, while option C accurately states that DNS is not meant for tunneling but does not answer the question about what a DNS tunnel is.