200-301 Question 218
Single answerYou are configuring a switch in a network that uses Rapid Spanning Tree Protocol (RSTP). During troubleshooting, you notice a specific port on the switch is in the 'Blocking' state. Which statement best explains the role of this port in the RSTP topology?
- A
The port is a designated port and is actively forwarding traffic.
- B
The port is an alternate port and is used as a backup path to the root bridge.
- C
The port is a root port and connects directly to the root bridge.
- D
The port is a disabled port and is administratively shut down.
Show answer and explanation
Correct answer: B
Explanation
In RSTP, an alternate port is in the blocking state and acts as a backup for the root port. It is not actively forwarding traffic but can quickly transition to the forwarding state if the primary path fails, ensuring faster convergence in the network topology.
- A. Incorrect.
This is incorrect because a designated port is in the forwarding state, not the blocking state.
- B. Correct.
This is correct because an alternate port in RSTP is in the blocking state and serves as a backup path to the root bridge.
- C. Incorrect.
This is incorrect because a root port connects directly to the root bridge and is in the forwarding state.
- D. Incorrect.
This is incorrect because a disabled port is administratively shut down and is not part of the RSTP topology.