Implementing Cisco Enterprise Advanced Routing and Services (ENARSI) — Question 83

When configuring Control Plane Policing on a router to protect it from malicious traffic, an engineer observes that the configured routing protocols start flapping on that device.
Which action in the Control Plane Policy prevents this problem in a production environment while achieving the security objective?

Answer options

• A. Set the conform-action and exceed-action to transmit initially to test the ACLs and transmit rates and apply the Control Plane Policy in the output direction.
• B. Set the conform-action and exceed-action to transmit initially to test the ACLs and transmit rates and apply the Control Plane Policy in the input direction.
• C. Set the conform-action to transmit and exceed-action to drop to test the ACLs and transmit rates and apply the Control Plane Policy in the input direction.
• D. Set the conform-action to transmit and exceed-action to drop to test the ACLs and transmit rates and apply the Control Plane Policy in the output direction.

Correct answer: B

Explanation

Option B is correct because applying the Control Plane Policy in the input direction allows the router to filter incoming traffic effectively without disrupting the routing protocols. Other options either apply the policy in the wrong direction or use actions that could lead to dropping packets essential for routing stability.