CCNA: Cisco Certified Network Associate — Question 458

What is a function of MAC learning on a switch?

Answer options

• A. MAC address learning is disabled by default on all VLANs.
• B. Frames received for a destination MAC address not listed in the address table are dropped.
• C. The MAC address table is used to populate the ARP table.
• D. A static MAC address is manually added to the MAC table.

Correct answer: D

Explanation

The correct answer, D, is accurate because manually adding a static MAC address ensures that the switch knows how to handle traffic for that specific address. Option A is incorrect since MAC learning is typically enabled by default. Option B is misleading because frames are not necessarily dropped; they may be flooded instead. Option C is also wrong as the MAC address table does not directly populate the ARP table.