Understanding Cisco Cybersecurity Fundamentals (SECFND, legacy) — Question 45

In which one of the following layers of the OSI model does the router primarily operate?

Answer options

• A. Layer 2
• B. Layer 3
• C. Layer 4
• D. Layer 7

Correct answer: B

Explanation

The correct answer is B, Layer 3, as routers operate at this layer to make forwarding decisions based on IP addresses. Options A (Layer 2), C (Layer 4), and D (Layer 7) refer to the Data Link, Transport, and Application layers respectively, which do not involve routing functionality.