- A
Modify the CoS-to-queue mapping using the 'mls qos srr-queue output cos-map' command
Correct because this command allows the engineer to map specific CoS values to specific queues, separating voice and video.
- B
Change the video traffic marking to DSCP AF41 and rely on DSCP-to-queue mapping
Why wrong: Incorrect because the switch uses CoS-to-queue mapping by default; DSCP mapping is not used unless explicitly configured.
- C
Apply a service policy that uses a priority queue for voice only
Why wrong: Incorrect because a priority queue does not change the queue assignment; it only provides strict priority within the queue.
- D
Increase the number of queues to eight
Why wrong: Incorrect because the number of queues is hardware-limited; adding more queues does not solve the mapping issue.
Quick Answer
The answer is to modify the CoS-to-queue mapping using the 'mls qos srr-queue output cos-map' command. This is correct because on a Catalyst 4500, the default CoS-to-queue mapping places CoS values 0-4 into queue 1, which is why video traffic (typically marked with CoS 4) shares the priority queue with voice (CoS 5). By re-mapping CoS 4 to queue 2 and CoS 5 to queue 1, you separate voice and video traffic into their designated queues while preserving the four-queue structure. On the ENCOR 350-401 exam, this tests your understanding of platform-specific QoS implementation, as the 4500 uses a different default mapping than the 3750 or 3850 series. A common trap is assuming that changing the CoS value alone will move traffic between queues—it will not, because the queue assignment is determined by the mapping, not the CoS mark itself. Remember the mnemonic: "CoS maps the mark, not the queue" to avoid confusing marking with mapping.
CCNP QoS Practice Question
This 350-401 practice question tests your understanding of qos. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 deploying QoS on a Cisco Catalyst 4500 switch to support four queues per port. The engineer wants to assign voice traffic to queue 1 (priority), video to queue 2, critical data to queue 3, and best-effort to queue 4. The switch is configured with the default CoS-to-queue mapping. However, video traffic is being placed in queue 1 along with voice. What should the engineer do to separate them?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"best"Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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 CoS-to-queue mapping using the 'mls qos srr-queue output cos-map' command
The correct answer is to modify the CoS-to-queue mapping using the 'mls qos srr-queue output cos-map' command to assign different CoS values to different queues.
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.
- ✓
Modify the CoS-to-queue mapping using the 'mls qos srr-queue output cos-map' command
Why this is correct
Correct because this command allows the engineer to map specific CoS values to specific queues, separating voice and video.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Change the video traffic marking to DSCP AF41 and rely on DSCP-to-queue mapping
- ✗
Apply a service policy that uses a priority queue for voice only
Why it's wrong here
Incorrect because a priority queue does not change the queue assignment; it only provides strict priority within the queue.
- ✗
Increase the number of queues to eight
Why it's wrong here
Incorrect because the number of queues is hardware-limited; adding more queues does not solve the mapping issue.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
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.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- 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 practitioner preparing for the 350-401 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which 350-401 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
- →
QoS — study guide chapter
Learn the concepts, then practise the questions
- →
QoS practice questions
Targeted practice on this topic area only
- →
All 350-401 questions
2,015 questions across all exam domains
- →
ENCOR 350-401 study guide
Full concept coverage aligned to exam objectives
- →
350-401 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
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.
FAQ
Questions learners often ask
What does this 350-401 question test?
QoS — This question tests QoS — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Modify the CoS-to-queue mapping using the 'mls qos srr-queue output cos-map' command — The correct answer is to modify the CoS-to-queue mapping using the 'mls qos srr-queue output cos-map' command to assign different CoS values to different queues.
What should I do if I get this 350-401 question wrong?
Identify which 350-401 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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 →
Last reviewed: Jun 18, 2026
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.
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.
Sign in to join the discussion.