Question 1,452 of 2,015

ACLs and CoPP →mediumMultiple ChoiceObjective-mapped

350-401 ACLs and CoPP Practice Question

This 350-401 practice question tests your understanding of acls and copp. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.

A network engineer is troubleshooting an issue where SSH access to a Cisco router from a specific management subnet (10.10.10.0/24) is intermittently failing. The router has a CoPP policy applied to the control plane. The engineer checks the CoPP statistics and sees that packets from the management subnet are being dropped by the control-plane service-policy. Which configuration change should the engineer make to allow SSH from the management subnet while still protecting the control plane?

Question 1mediummultiple choice

Study the full ACL explanation →

A
Modify the CoPP ACL to include a permit statement for TCP port 22 from 10.10.10.0/24 before the deny statement.
Correct because this allows SSH traffic from the management subnet to be classified and permitted by the CoPP policy, preventing drops.
B
Remove the deny statement from the CoPP ACL to allow all traffic.
Why wrong: Incorrect because removing the deny statement would allow all traffic to the control plane, defeating the purpose of CoPP.
C
Increase the police rate for the CoPP class that matches SSH traffic.
Why wrong: Incorrect because the issue is not rate limiting; the traffic is being dropped by an ACL deny, not policed.
D
Remove the CoPP policy from the control plane and rely on interface ACLs.
Why wrong: Incorrect because removing CoPP leaves the control plane vulnerable to attacks; interface ACLs alone may not provide sufficient protection.

Full breakdown with real-world context →

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

✓

Modify the CoPP ACL to include a permit statement for TCP port 22 from 10.10.10.0/24 before the deny statement.

The correct answer adds an ACL entry to permit SSH from the management subnet before the deny statement, ensuring that SSH traffic is matched by the CoPP policy and not dropped. Option B is incorrect because removing the deny statement would leave the control plane unprotected. Option C is incorrect because increasing the police rate might not resolve the issue if the traffic is being dropped by an ACL deny. Option D is incorrect because removing the CoPP policy entirely removes all protection.

Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

Answer analysis

Option-by-option breakdown

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

✓
Modify the CoPP ACL to include a permit statement for TCP port 22 from 10.10.10.0/24 before the deny statement.
Why this is correct
Correct because this allows SSH traffic from the management subnet to be classified and permitted by the CoPP policy, preventing drops.
Related concept
CIDR notation defines the prefix length.
✗
Remove the deny statement from the CoPP ACL to allow all traffic.
Why it's wrong here
Incorrect because removing the deny statement would allow all traffic to the control plane, defeating the purpose of CoPP.
✗
Increase the police rate for the CoPP class that matches SSH traffic.
Why it's wrong here
Incorrect because the issue is not rate limiting; the traffic is being dropped by an ACL deny, not policed.
✗
Remove the CoPP policy from the control plane and rely on interface ACLs.
Why it's wrong here
Incorrect because removing CoPP leaves the control plane vulnerable to attacks; interface ACLs alone may not provide sufficient protection.

Common exam traps

Common exam trap: usable hosts are not the same as total addresses

Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.

Detailed technical explanation

How to think about this question

Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.

KKey Concepts to Remember

CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.

TExam Day Tips

Write the block size before choosing the subnet.
Check whether the question asks for hosts, subnets or a specific address range.
Do not confuse /24, /25, /26 and /27 host counts.

Key takeaway

Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

Real-world example

How this comes up in practice

A security administrator must allow nursing staff to reach a patient records server while blocking access from the guest Wi-Fi VLAN. After applying an extended ACL, traffic is still blocked from nursing workstations. The ACL was applied outbound instead of inbound on the wrong interface. Questions like this test ACL direction and placement rules.

What to study next

Got this wrong? Here's your next step.

Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 350-401 subnetting questions on CIDR, address ranges, and subnet selection.

Related 350-401 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Architecture practice questions

Practise 350-401 questions linked to Architecture.

Enterprise Network Design practice questions

Practise 350-401 questions linked to Enterprise Network Design.

SD-Access Architecture practice questions

Practise 350-401 questions linked to SD-Access Architecture.

SD-WAN Architecture practice questions

Practise 350-401 questions linked to SD-WAN Architecture.

QoS Architecture practice questions

Practise 350-401 questions linked to QoS Architecture.

Virtualization practice questions

Practise 350-401 questions linked to Virtualization.

Network Function Virtualization practice questions

Practise 350-401 questions linked to Network Function Virtualization.

Virtual Machines and Hypervisors practice questions

Practise 350-401 questions linked to Virtual Machines and Hypervisors.

VRF and Path Isolation practice questions

Practise 350-401 questions linked to VRF and Path Isolation.

Infrastructure practice questions

Practise 350-401 questions linked to Infrastructure.

OSPF practice questions

Practise 350-401 questions linked to OSPF.

BGP practice questions

Practise 350-401 questions linked to BGP.

Practice this exam

Start a free 350-401 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

350-401 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this 350-401 question test?

ACLs and CoPP — This question tests ACLs and CoPP — CIDR notation defines the prefix length..

What is the correct answer to this question?

The correct answer is: Modify the CoPP ACL to include a permit statement for TCP port 22 from 10.10.10.0/24 before the deny statement. — The correct answer adds an ACL entry to permit SSH from the management subnet before the deny statement, ensuring that SSH traffic is matched by the CoPP policy and not dropped. Option B is incorrect because removing the deny statement would leave the control plane unprotected. Option C is incorrect because increasing the police rate might not resolve the issue if the traffic is being dropped by an ACL deny. Option D is incorrect because removing the CoPP policy entirely removes all protection.

What should I do if I get this 350-401 question wrong?

What is the key concept behind this question?

CIDR notation defines the prefix length.

About these practice questions

Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Keep practising

Question Discussion

Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.

Loading comments…

This 350-401 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 350-401 exam.