ICND1: Interconnecting Cisco Networking Devices Part 1 (CCENT, legacy) — Question 56

At which layer of the OSI model does the protocol that provides the information that is displayed by the show cdp neighbors command operate?

Answer options

• A. data link
• B. application
• C. network
• D. transport
• E. physical

Correct answer: A

Explanation

The correct answer is A, data link, because the Cisco Discovery Protocol (CDP) operates at this layer to provide information about directly connected devices. The other layers—application, network, transport, and physical—do not specifically deal with neighbor discovery in the same way as the data link layer does.