300-420 Question 258
Single answerA network engineer is tasked with implementing QoS on a WAN link to ensure that critical traffic adheres to bandwidth limitations. They decide to use policing to enforce these constraints. Which of the following statements about policing is TRUE in this scenario?
- A
Policing drops packets that exceed the configured traffic rate.
- B
Policing dynamically adjusts traffic rates to ensure all traffic is transmitted.
- C
Policing re-marks packets that exceed the configured traffic rate but does not drop them.
- D
Policing queues excess traffic until bandwidth becomes available.
Show answer and explanation
Correct answer: A
Explanation
Policing is a QoS mechanism used to enforce bandwidth limits by monitoring traffic rates and taking action on packets that exceed the configured limits. The default action of policing is to drop excess packets, though it can also re-mark them if configured. Unlike shaping, policing does not buffer or queue excess traffic; it enforces strict compliance with the rate policy.
- A. Correct.
Correct. Policing enforces traffic rate limits by dropping packets that exceed the configured rate, ensuring that the traffic adheres to the policy.
- B. Incorrect.
Incorrect. Policing does not dynamically adjust traffic rates. It is a strict enforcement mechanism that either drops or re-marks excess traffic.
- C. Incorrect.
Incorrect. While policing can optionally re-mark packets, it is not the default or sole behavior. Excess traffic is typically dropped unless explicitly configured otherwise.
- D. Incorrect.
Incorrect. Policing does not use queuing mechanisms. It enforces rate limits by either dropping or re-marking traffic.