CCNA: Cisco Certified Network Associate — Question 941

What is the operating mode and role of a backup port on a shared LAN segment in Rapid PVST+?

Answer options

• A. learning mode and provides the shortest path toward the root bridge handling traffic away from the LAN
• B. blocking mode and provides an alternate path toward the designated bridge
• C. forwarding mode and provides the lowest-cost path to the root bridge for each VLAN
• D. listening mode and provides an alternate path toward the root bridge

Correct answer: B

Explanation

The correct answer is B because a backup port operates in blocking mode, preventing traffic from flowing until needed, while providing an alternate path to the designated bridge. The other options describe different port roles or functions that do not accurately represent the role of a backup port in Rapid PVST+.