This 350-601 practice question tests your understanding of storage network. Examine the command output carefully: the correct answer depends on what the output actually shows, not on general recall alone. 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 company is consolidating its storage network into a single fabric using a Cisco MDS 9509. They want to use VSANs to isolate different departments. The VSANs will be 10, 20, and 30. They have a single ISL between two MDS switches. The engineers want to carry all three VSANs over the ISL. They configure both ends of the ISL as E ports and enable trunking. After configuration, they notice that only VSAN 10 traffic passes over the ISL. The other VSANs appear isolated. The show vsan membership shows all three VSANs are present on both switches. The show interface trunk on the ISL shows that the trunk is up but only VSAN 10 is allowed. What is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The allowed VSAN list on the trunk port is limited to only VSAN 10
The show interface trunk output indicates that only VSAN 10 is in the allowed list. The allowed VSAN list on the trunk port must be configured to include all three VSANs. The trunk mode (on/desirable) does not limit VSANs. Error-disabled would show in different status. VSAN membership on the interface is not applicable for trunk ports.
Key principle: A trunk being up does not mean the VLAN is allowed across it. Always verify the allowed VLAN list and whether the VLAN exists on both switches.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The other VSANs are not configured on the trunk interface
Why it's wrong here
VSANs are configured switch-wide, not per interface.
✓
The allowed VSAN list on the trunk port is limited to only VSAN 10
Why this is correct
The allowed VSAN list must be explicitly configured to include VSAN 20 and 30.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Access ports place end devices into a single VLAN.
✗
The trunk mode is set to 'on' instead of 'desirable'/'auto'
Why it's wrong here
Trunk mode 'on' enables trunking but does not restrict allowed VSANs.
✗
The ISL is in an error-disabled state for VSAN 20 and 30
Why it's wrong here
Error-disable would prevent traffic on those VSANs, but the trunk status shows only VSAN allowed.
Common exam traps
Common exam trap: an active trunk can still block the VLAN you need
A trunk being up does not prove every VLAN is crossing it. Check allowed VLAN lists, native VLAN mismatch, VLAN existence and access-port assignment.
Trap categories for this question
Command / output trap
Error-disable would prevent traffic on those VSANs, but the trunk status shows only VSAN allowed.
Detailed technical explanation
How to think about this question
VLAN questions usually combine access-port and trunking clues. The key is to identify whether the issue is local to one switchport, caused by the trunk, or caused by the VLAN not existing where it needs to exist.
KKey Concepts to Remember
Access ports place end devices into a single VLAN.
Trunk ports carry multiple VLANs between switches.
Allowed VLAN lists decide which VLANs can cross a trunk.
Native VLAN mismatch can create confusing symptoms.
TExam Day Tips
→Use show vlan brief to verify access VLANs.
→Use show interfaces trunk to verify trunk state and allowed VLANs.
→Do not treat every same-VLAN issue as a routing problem.
Key takeaway
A trunk being up does not mean the VLAN is allowed across it. Always verify the allowed VLAN list and whether the VLAN exists on both switches.
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.
Review VLAN allowed lists, native VLAN mismatch detection, and how to verify VLAN membership with show vlan brief and show interfaces trunk. Then practise related 350-601 questions on switching, trunking, and access-port configuration.
Storage Network — This question tests Storage Network — Access ports place end devices into a single VLAN..
What is the correct answer to this question?
The correct answer is: The allowed VSAN list on the trunk port is limited to only VSAN 10 — The show interface trunk output indicates that only VSAN 10 is in the allowed list. The allowed VSAN list on the trunk port must be configured to include all three VSANs. The trunk mode (on/desirable) does not limit VSANs. Error-disabled would show in different status. VSAN membership on the interface is not applicable for trunk ports.
What should I do if I get this 350-601 question wrong?
Review VLAN allowed lists, native VLAN mismatch detection, and how to verify VLAN membership with show vlan brief and show interfaces trunk. Then practise related 350-601 questions on switching, trunking, and access-port configuration.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Access ports place end devices into a single VLAN.
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 →
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.
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.
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.