200-301 Question 210
Single answerA network engineer has configured Rapid PVST+ on multiple switches in a network. After reviewing the topology, the engineer notices that one of the switches is not becoming the root bridge as expected. Which configuration change should the engineer make to ensure the correct switch becomes the root bridge?
- A
Increase the priority value of the desired root bridge.
- B
Decrease the priority value of the desired root bridge.
- C
Enable PortFast on all interfaces of the desired root bridge.
- D
Configure BPDU guard on the desired root bridge.
Show answer and explanation
Correct answer: B
Explanation
In Rapid PVST+, the switch with the lowest bridge priority becomes the root bridge. If the desired switch is not becoming the root bridge, the priority value of that switch must be lowered to ensure it takes precedence over others in the election process. Lower priority values are preferred, with the default being 32768.
- A. Incorrect.
Increasing the priority value makes the switch less likely to become the root bridge since lower priority values are preferred in Spanning Tree elections.
- B. Correct.
Decreasing the priority value makes the switch more likely to become the root bridge because Rapid PVST+ selects the switch with the lowest priority as the root bridge.
- C. Incorrect.
Enabling PortFast is used to speed up the transition of ports to the forwarding state but has no effect on root bridge election.
- D. Incorrect.
Configuring BPDU guard prevents unintended devices from participating in the Spanning Tree Protocol but does not influence root bridge election.