300-410 Question 231
Single answerA network engineer implemented Control Plane Policing (CoPP) on a router to prioritize management traffic such as SSH and SNMP. After the configuration, users report that they are unable to establish SSH sessions to the router, but SNMP monitoring appears to be working fine. Which of the following is the most likely cause of the issue?
- A
The CoPP policy does not include a class map for SSH traffic.
- B
The CoPP policy is incorrectly dropping SNMP traffic.
- C
The CoPP policy exceeds the hardware capacity of the router.
- D
The CoPP policy is incorrectly configured for HTTP instead of SSH.
Show answer and explanation
Correct answer: A
Explanation
Control Plane Policing (CoPP) is used to control the amount of traffic handled by the control plane. In this scenario, the issue is specific to SSH traffic, which indicates that the CoPP policy likely does not correctly classify or prioritize SSH packets. Ensuring that a class map for SSH traffic is defined and properly permitted in the CoPP policy would resolve the issue.
- A. Correct.
If the CoPP policy does not include a specific class map for SSH traffic, or if the SSH traffic is incorrectly categorized, the router will drop SSH packets, preventing SSH sessions from being established.
- B. Incorrect.
In this scenario, SNMP traffic is reported to be working fine, so the CoPP policy is not dropping SNMP traffic. This cannot be the correct answer.
- C. Incorrect.
While exceeding hardware capacity can cause issues, this would likely result in failures for all traffic types, not just SSH. The issue is specific to SSH in this case.
- D. Incorrect.
A CoPP policy misconfigured for HTTP would not affect SSH traffic unless there is a misclassification or priority issue. However, there is no indication that HTTP traffic is involved in this scenario.