CCNA: Cisco Certified Network Associate — Question 1083

How does MAC learning function?

Answer options

• A. overwrites the known source MAC address in the address table
• B. enabled by default on all VLANs and interfaces
• C. protects against denial of service attacks
• D. forwards frames to a neighbor port using CDP

Correct answer: B

Explanation

The correct answer, B, indicates that MAC learning is automatically enabled on all VLANs and interfaces for efficient network operation. Options A, C, and D describe functionalities unrelated to the basic operation of MAC learning, which specifically focuses on building and maintaining the MAC address table.