200-301 Question 223
Single answerA network engineer configures PortFast on an access port connected to a user's PC. Which of the following describes the primary benefit of enabling PortFast on this port?
- A
It enables the port to bypass the Listening and Learning states and transition directly to the Forwarding state.
- B
It prevents the port from ever participating in the Spanning Tree Protocol (STP).
- C
It allows the port to dynamically negotiate trunking with the connected device.
- D
It ensures the port remains in the Blocking state to avoid network loops.
Show answer and explanation
Correct answer: A
Explanation
PortFast is a feature that optimizes STP behavior for access ports connected to end-user devices. By skipping the Listening and Learning states, PortFast enables the port to transition immediately to the Forwarding state, reducing the time it takes for the device to start communicating on the network. However, the port still participates in STP and can revert to other states if a loop is detected.
- A. Correct.
Correct: PortFast allows the port to bypass the Listening and Learning states of STP and immediately transition to the Forwarding state, reducing delay for end-user devices.
- B. Incorrect.
Incorrect: PortFast does not prevent the port from participating in STP. It only modifies the port's behavior to optimize it for end-user devices.
- C. Incorrect.
Incorrect: PortFast is unrelated to trunking or dynamic negotiation. It is specifically designed to optimize STP behavior for access ports.
- D. Incorrect.
Incorrect: PortFast does not keep the port in the Blocking state. It ensures rapid forwarding for end-user devices while still allowing STP to detect loops if necessary.