Question 367 of 500
SecurityhardMultiple SelectObjective-mapped

Quick Answer

The correct answer is that CoPP is configured using the 'control-plane' sub-mode with policy-maps, and it can rate-limit control-plane traffic such as ICMP unreachable messages. This works because Control Plane Policing on a Nexus 9000 switch uses a modular QoS CLI (MQC) approach: you define class-maps to match specific control-plane protocols, then apply a policy-map with a police action under the 'control-plane' sub-mode to limit the rate of those packets, protecting the CPU from floods. On the Cisco DCCOR 350-601 exam, this topic tests your understanding of how to safeguard the supervisor engine from denial-of-service attacks without disrupting legitimate traffic—a common trap is confusing CoPP with hardware rate-limiters or thinking it applies to data-plane forwarding. Remember the memory tip: "CoPP cops the control plane, not the data plane," meaning you always apply the policy under 'control-plane' and never under a physical interface.

350-601 Security Practice Question

This 350-601 practice question tests your understanding of security. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

Which TWO statements are true about Control Plane Policing (CoPP) on a Cisco Nexus 9000 switch? (Choose two.)

Question 1hardmulti select
Study the full ACL explanation →

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

CoPP can be used to limit the rate of ICMP unreachable messages.

Option A is correct because CoPP can rate-limit control-plane traffic such as ICMP unreachable messages. By applying a policy-map in the 'control-plane' sub-mode, you can define class-maps that match specific control-plane protocols (e.g., ICMP) and then police their rate to prevent CPU overload from floods of such packets.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • CoPP can be used to limit the rate of ICMP unreachable messages.

    Why this is correct

    ICMP unreachable messages can be rate-limited with CoPP to prevent DoS.

    Related concept

    Read the scenario before looking for a memorised answer.

  • CoPP automatically drops all unknown unicast traffic.

    Why it's wrong here

    Unknown unicast flooding is controlled by other features, not CoPP.

  • CoPP is configured using the 'control-plane' sub-mode with policy-maps.

    Why this is correct

    CoPP is configured by creating a policy-map and applying it under the 'control-plane' configuration mode.

    Related concept

    Read the scenario before looking for a memorised answer.

  • CoPP applies only to traffic destined to the switch management IP.

    Why it's wrong here

    CoPP protects the entire control plane, including routing protocol traffic, not just management IP.

  • CoPP can be used to prioritize OSPF traffic over SSH.

    Why it's wrong here

    CoPP polices (limits) traffic, but prioritization is achieved with QoS, not CoPP.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Cisco often tests the misconception that CoPP is only for management IP traffic or that it can prioritize traffic, when in fact it is a policing mechanism for all control-plane traffic and does not provide prioritization.

Detailed technical explanation

How to think about this question

CoPP uses MQC (Modular QoS CLI) to classify traffic with class-maps and apply actions like 'police' in a policy-map under the 'control-plane' sub-mode. For example, you can create a class-map matching 'icmp' and then police it to a specific rate (e.g., 100 pps) to protect the CPU from ICMP floods. In real-world scenarios, CoPP is critical for mitigating control-plane DoS attacks while allowing legitimate routing protocol traffic (e.g., OSPF, BGP) to pass through.

KKey Concepts to Remember

  • Read the scenario before looking for a memorised answer.
  • Find the constraint that changes the correct option.
  • Eliminate answers that are true in general but not in this case.

TExam Day Tips

  • Watch for words such as best, first, most likely and least administrative effort.
  • Review why wrong options are wrong, not only why the correct option is correct.

Key takeaway

Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Real-world example

How this comes up in practice

A network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Related practice questions

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FAQ

Questions learners often ask

What does this 350-601 question test?

Security — This question tests Security — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: CoPP can be used to limit the rate of ICMP unreachable messages. — Option A is correct because CoPP can rate-limit control-plane traffic such as ICMP unreachable messages. By applying a policy-map in the 'control-plane' sub-mode, you can define class-maps that match specific control-plane protocols (e.g., ICMP) and then police their rate to prevent CPU overload from floods of such packets.

What should I do if I get this 350-601 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Same concept, more angles

2 more ways this is tested on 350-601

These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.

Variation 1. An engineer needs to secure the management plane on a Cisco Nexus 9000 switch. Which feature should be configured to restrict access to the switch's management interface based on source IP?

easy
  • A.Enable DHCP snooping on the management VLAN.
  • B.Enable port security on the management interface.
  • C.Configure AAA to require two-factor authentication.
  • D.Configure a management CoPP policy to rate-limit and permit only specific source IPs.

Why D: Option D is correct because a management Control Plane Policing (CoPP) policy on a Cisco Nexus 9000 switch allows the engineer to explicitly permit or deny traffic destined to the management interface based on source IP addresses. CoPP applies QoS policies to control plane traffic, effectively restricting management plane access by rate-limiting or dropping packets from unauthorized sources before they reach the CPU.

Variation 2. Refer to the exhibit. The CoPP policy above is applied. Which traffic is most likely to be dropped?

hard
  • A.Both ICMP and class-default traffic that exceed their rates
  • B.ICMP traffic that exceeds 1000 bps
  • C.class-default traffic that exceeds 20000 bps
  • D.OSPF traffic that exceeds 5000 bps

Why B: Option B is correct because the CoPP policy explicitly defines a class-map for ICMP traffic with a police rate of 1000 bps. Any ICMP traffic exceeding this rate is dropped due to the 'drop' action in the police command. The other classes (OSPF and class-default) have higher rates and are not as constrained, making ICMP the most likely to be dropped when exceeded.

Last reviewed: Jun 24, 2026

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This 350-601 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-601 exam.