Question 414 of 505
Network FundamentalshardMultiple ChoiceObjective-mapped

200-901 Network Fundamentals Practice Question

This 200-901 practice question tests your understanding of network fundamentals. 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.

Exhibit

SwitchA# show running-config interface port-channel1
!
interface Port-channel1
 switchport mode trunk
 switchport trunk allowed vlan 1-100,200

SwitchB# show running-config interface port-channel1
!
interface Port-channel1
 switchport mode trunk
 switchport trunk allowed vlan 1-50,100-199

Refer to the exhibit. Both switches are configured with EtherChannel. Which statement is true about VLAN traffic across the trunk?

Question 1hardmultiple choice
Open the full VLAN trunking answer →

Exhibit

SwitchA# show running-config interface port-channel1
!
interface Port-channel1
 switchport mode trunk
 switchport trunk allowed vlan 1-100,200

SwitchB# show running-config interface port-channel1
!
interface Port-channel1
 switchport mode trunk
 switchport trunk allowed vlan 1-50,100-199

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

VLAN 100 traffic is allowed across the trunk.

The correct answer is D because the exhibit shows that VLAN 100 is configured on both switches and is included in the allowed VLAN list on the trunk. EtherChannel does not affect VLAN filtering; the trunk's allowed VLAN list determines which VLANs can traverse the link. Since VLAN 100 is explicitly permitted, its traffic is allowed across the trunk.

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.

  • VLAN 150 traffic is allowed across the trunk.

    Why it's wrong here

    VLAN 150 is not in SwitchA's allowed list.

  • VLAN 50 traffic is blocked across the trunk.

    Why it's wrong here

    VLAN 50 is allowed on both switches.

  • VLAN 200 traffic is allowed across the trunk.

    Why it's wrong here

    VLAN 200 is not allowed on SwitchB.

  • VLAN 100 traffic is allowed across the trunk.

    Why this is correct

    VLAN 100 is allowed on both switches (1-100 on A, 100-199 on B).

    Related concept

    Read the scenario before looking for a memorised answer.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Cisco often tests the misconception that EtherChannel overrides or bypasses VLAN trunk filtering, but in reality, the allowed VLAN list on the port-channel interface still controls which VLANs are permitted across the aggregated link.

Detailed technical explanation

How to think about this question

EtherChannel aggregates multiple physical links into a single logical interface, but VLAN trunking behavior (including allowed VLAN lists) is applied to the port-channel interface itself, not the individual member ports. The 'switchport trunk allowed vlan' command filters traffic at Layer 2, and any VLAN not in the list is dropped. In real-world scenarios, misconfigured allowed VLAN lists are a common cause of connectivity issues, especially when adding new VLANs to a network.

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 help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.

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

Related 200-901 practice-question pages

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

Practice this exam

Start a free 200-901 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 200-901 question test?

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

What is the correct answer to this question?

The correct answer is: VLAN 100 traffic is allowed across the trunk. — The correct answer is D because the exhibit shows that VLAN 100 is configured on both switches and is included in the allowed VLAN list on the trunk. EtherChannel does not affect VLAN filtering; the trunk's allowed VLAN list determines which VLANs can traverse the link. Since VLAN 100 is explicitly permitted, its traffic is allowed across the trunk.

What should I do if I get this 200-901 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.

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

Last reviewed: Jun 24, 2026

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…

Sign in to join the discussion.

This 200-901 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 200-901 exam.