300-410 Question 230
Single answerA network administrator notices that OSPF neighbor relationships are not forming between routers after implementing Control Plane Policing (CoPP). Upon reviewing the CoPP configuration, they observe the following policy applied to the control plane:
class-map match-any MANAGEMENT match protocol telnet match protocol ssh match protocol https match protocol snmp
policy-map CONTROL-PLANE-POLICY class MANAGEMENT police 1000000 class class-default police 500000
What is the most likely reason for the OSPF issue?
- A
OSPF traffic is being dropped because it is not explicitly permitted in the CoPP policy.
- B
The policing rate for the MANAGEMENT class is too low to handle OSPF traffic.
- C
The CoPP policy is not applied to the control plane of the router.
- D
The class-default policing rate is too high, causing OSPF traffic to be prioritized incorrectly.
Show answer and explanation
Correct answer: A
Explanation
Control Plane Policing (CoPP) is used to protect the control plane by managing and policing traffic. In this scenario, OSPF traffic is failing because it is not explicitly permitted in the CoPP policy. By default, unclassified traffic falls into the class-default, which is policed at a lower rate and may be dropped. To resolve this, OSPF should be explicitly added to the CoPP configuration under a class-map.
- A. Correct.
OSPF is not listed as a protocol in the MANAGEMENT class, and since it is not explicitly permitted, its traffic falls into the class-default, which is policed at a lower rate and likely being dropped.
- B. Incorrect.
While the policing rate could affect traffic, in this case, OSPF is not included in the CoPP policy, so it is not a rate issue but a classification issue.
- C. Incorrect.
The CoPP policy is already applied to the control plane, as indicated in the scenario. The root cause lies in the classification of protocols in the policy.
- D. Incorrect.
The policing rate for the class-default is lower than the MANAGEMENT class, which would lead to traffic being dropped, but the issue is not due to prioritization but rather OSPF traffic not being explicitly allowed.