- A
A VLAN can be created using the 'vlan vlan-id' command in global configuration mode.
This is the standard method to create a VLAN; the switch then enters VLAN configuration sub-mode.
- B
The 'show vlan brief' command displays all VLANs, including the reserved VLANs 1002-1005.
The output includes all VLANs, even those that are reserved and cannot be deleted, such as VLANs 1002-1005.
- C
VLAN 1 can be deleted from the switch.
Why wrong: VLAN 1 is the default VLAN and cannot be deleted; it is always present.
- D
The 'switchport access vlan' command automatically creates the VLAN if it does not already exist.
On many Cisco switches, assigning a port to a non-existent VLAN will cause the VLAN to be created automatically (VLAN database is updated).
- E
The 'show interfaces trunk' command shows only the trunking interfaces and their native VLAN.
Why wrong: The command shows trunking interfaces, the allowed VLAN list, and the native VLAN, but also the trunking mode and encapsulation; it does not show only the native VLAN.
Quick Answer
The answer is that the 'switchport access vlan' command can automatically create the VLAN if it does not already exist on certain Cisco platforms. This behavior occurs because the command triggers VLAN creation dynamically when applied to an access port, though it is not universal across all IOS versions—some require the VLAN to be pre-created in global configuration mode. On the ENCOR 350-401 exam, this concept tests your understanding of VLAN lifecycle management and the reserved status of VLAN 1 and VLANs 1002-1005, which cannot be deleted. A common trap is assuming all VLANs must be manually created before assignment, but the 'show vlan brief' command will reveal any auto-created VLANs, while 'show interfaces trunk' verifies allowed VLAN lists on trunk links. Remember the mnemonic: "Access auto-creates, trunk only lists, and 1 plus 1002-1005 are reserved fists."
CCNP VLANs and Trunking Practice Question
This 350-401 practice question tests your understanding of vlans and trunking. 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.
Which three statements about VLAN configuration and verification are true? (Choose three.)
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
A VLAN can be created using the 'vlan vlan-id' command in global configuration mode.
VLANs can be created in global configuration mode or in VLAN database mode (though the latter is deprecated). The 'show vlan brief' command displays active VLANs and their ports. VLAN 1 and VLANs 1002-1005 are reserved and cannot be deleted. The 'switchport access vlan' command assigns a port to a VLAN, but the VLAN must exist first or it will be created automatically on some platforms. The 'show interfaces trunk' command shows trunking interfaces and allowed VLAN lists.
Key principle: Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
A VLAN can be created using the 'vlan vlan-id' command in global configuration mode.
Why this is correct
This is the standard method to create a VLAN; the switch then enters VLAN configuration sub-mode.
Related concept
Authentication checks who the user is.
- ✓
The 'show vlan brief' command displays all VLANs, including the reserved VLANs 1002-1005.
Why this is correct
The output includes all VLANs, even those that are reserved and cannot be deleted, such as VLANs 1002-1005.
Related concept
Authentication checks who the user is.
- ✗
VLAN 1 can be deleted from the switch.
Why it's wrong here
VLAN 1 is the default VLAN and cannot be deleted; it is always present.
- ✓
The 'switchport access vlan' command automatically creates the VLAN if it does not already exist.
Why this is correct
On many Cisco switches, assigning a port to a non-existent VLAN will cause the VLAN to be created automatically (VLAN database is updated).
Related concept
Authentication checks who the user is.
- ✗
The 'show interfaces trunk' command shows only the trunking interfaces and their native VLAN.
Why it's wrong here
The command shows trunking interfaces, the allowed VLAN list, and the native VLAN, but also the trunking mode and encapsulation; it does not show only the native VLAN.
Common exam traps
Common exam trap: authentication is not authorization
Logging in proves the user can authenticate. It does not automatically mean the user is allowed to enter privileged or configuration mode. Watch for AAA authorization, privilege level and command authorization details.
Trap categories for this question
Command / output trap
The command shows trunking interfaces, the allowed VLAN list, and the native VLAN, but also the trunking mode and encapsulation; it does not show only the native VLAN.
Detailed technical explanation
How to think about this question
This kind of question is testing the difference between identity and permission. A user may successfully log in to a router because authentication is working, but still fail to enter configuration mode because authorization is missing, misconfigured or mapped to a lower privilege level.
KKey Concepts to Remember
- Authentication checks who the user is.
- Authorization controls what the user is allowed to do after login.
- Privilege levels affect access to EXEC and configuration commands.
- AAA, TACACS+ and RADIUS can separate login success from command access.
TExam Day Tips
- Do not assume successful login means full administrative access.
- Look for words such as cannot enter configuration mode, privilege level, authorization or command access.
- Separate login problems from permission problems before choosing the answer.
Key takeaway
Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
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 Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related 350-401 questions on access control and AAA configuration.
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VLANs and Trunking — study guide chapter
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FAQ
Questions learners often ask
What does this 350-401 question test?
VLANs and Trunking — This question tests VLANs and Trunking — Authentication checks who the user is..
What is the correct answer to this question?
The correct answer is: A VLAN can be created using the 'vlan vlan-id' command in global configuration mode. — VLANs can be created in global configuration mode or in VLAN database mode (though the latter is deprecated). The 'show vlan brief' command displays active VLANs and their ports. VLAN 1 and VLANs 1002-1005 are reserved and cannot be deleted. The 'switchport access vlan' command assigns a port to a VLAN, but the VLAN must exist first or it will be created automatically on some platforms. The 'show interfaces trunk' command shows trunking interfaces and allowed VLAN lists.
What should I do if I get this 350-401 question wrong?
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related 350-401 questions on access control and AAA configuration.
What is the key concept behind this question?
Authentication checks who the user is.
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 →
Same concept, more angles
1 more ways this is tested on 350-401
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. Which two statements about VLAN configuration and verification on a Cisco IOS switch are true? (Choose two.)
easy- ✓ A.VLAN 1 and VLANs 1002-1005 cannot be deleted.
- ✓ B.The 'show vlan brief' command only displays VLANs that have been created on the switch.
- C.The 'switchport access vlan 10' command automatically creates VLAN 10 if it does not exist.
- D.The 'no switchport' command on a switch port places it into the default VLAN.
- E.Extended VLANs (1006-4094) are stored in the vlan.dat file by default.
Why A: Correct: A is true because VLANs 1 and 1002-1005 are reserved (default) and cannot be deleted. B is true because 'show vlan brief' displays only VLANs that exist in the VLAN database, not all possible VLANs. C is incorrect because the 'switchport access vlan' command assigns a port to a VLAN, but the VLAN must already exist or be created first; the command does not automatically create the VLAN. D is incorrect because 'no switchport' converts the interface to a Layer 3 routed port, which does not participate in VLANs. E is incorrect because the extended VLAN range (1006-4094) is not saved in vlan.dat by default; they are stored in the running configuration.
Keep practising
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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.
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