Certified Network Defender (CND) — Question 45

The Circuit-level gateway firewall technology functions at which of the following OSI layer?

Answer options

• A. Transport layer
• B. Data-link layer
• C. Session layer
• D. Network layer

Correct answer: C

Explanation

The Circuit-level gateway firewall operates at the Session layer (Layer 5) of the OSI model, managing sessions between hosts. Options A, B, and D refer to different layers that do not handle session management, making them incorrect in this context.