The correct answer is that the design purpose of configuring `switchport voice vlan 150` alongside `switchport access vlan 20` is to separate voice and data traffic on the same edge port by assigning them to different VLANs. This separation is achieved because the Cisco IP phone, which typically contains a small internal switch, tags its own voice traffic with VLAN 150 while leaving the attached workstation’s untagged traffic in the access VLAN 20. On the CCNA 200-301 v2 exam, this concept tests your understanding of the voice VLAN feature as a specialized access port behavior, not a trunk—a common trap is to mistakenly think the port becomes a trunk, but the phone’s CDP or LLDP negotiation keeps the link operating as an access port with a separate voice VLAN. A helpful memory tip is “voice tags, data untags,” meaning the phone tags its own frames for the voice VLAN while the PC’s frames remain untagged in the native access VLAN.
CCNA Switching and Network Access Practice Question
This 200-301 practice question tests your understanding of switching and network access. 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. A key principle to apply: a switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port.. 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 switch port is configured with `switchport voice vlan 150` and `switchport access vlan 20`. Which statement best explains the design purpose?
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 the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
It separates voice and data traffic on the same edge port by assigning them to different VLANs.
The design purpose is to let the switch support a phone and an attached workstation on the same physical access port while placing their traffic into different VLANs. In practical terms, the phone can use the voice VLAN while the user's data traffic uses the access VLAN. This is a common enterprise edge design for IP telephony.
The key idea is role separation on one port, not trunking the port as a normal inter-switch link.
Key principle: A switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
It separates voice and data traffic on the same edge port by assigning them to different VLANs.
Why this is correct
This is correct because that is the classic voice-VLAN access-port design.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
A switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port.
✗
It turns the port into a routed WAN interface.
Why it's wrong here
This is wrong because the configuration is for a switched access/voice-port role.
When this WOULD be correct
In a different scenario, a question might ask about the configuration of a switch port in a router-on-a-stick setup, where the context involves routing between VLANs. In that case, a response indicating that the port is configured as a routed WAN interface could be correct if it explicitly states that the port is configured for inter-VLAN routing.
✗
It forces the phone to use CAPWAP before receiving power.
Why it's wrong here
This is wrong because CAPWAP is unrelated here.
When this WOULD be correct
If the question were about the configuration of a wireless access point that requires a specific protocol for power delivery and management, such as CAPWAP, then this option could be correct. For example, a question might ask about the setup of a VoIP phone connected to a wireless network that utilizes CAPWAP for device management.
✗
It makes VLAN 150 the native VLAN on all trunks automatically.
Why it's wrong here
This is wrong because the command affects the edge port, not all trunks.
When this WOULD be correct
In a different question, if it asked about the behavior of a switch when configuring a trunk port with 'switchport trunk native vlan 150', this option would be correct as it would indicate that VLAN 150 is set as the native VLAN for all trunk links.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓It separates voice and data traffic on the same edge port by assigning them to different VLANs.Correct answer▾
Why this is correct
This is correct because that is the classic voice-VLAN access-port design.
✗It turns the port into a routed WAN interface.Wrong answer — click to see why▾
Why this is wrong here
The commands `switchport voice vlan 150` and `switchport access vlan 20` are used on a Layer 2 switch port, not a routed interface. A routed WAN interface would require `no switchport` and an IP address configuration, which is not present here.
★ When this WOULD be the correct answer
In a different scenario, a question might ask about the configuration of a switch port in a router-on-a-stick setup, where the context involves routing between VLANs. In that case, a response indicating that the port is configured as a routed WAN interface could be correct if it explicitly states that the port is configured for inter-VLAN routing.
Why candidates choose this
Students might confuse the term 'voice VLAN' with a WAN interface because both involve voice traffic, but the commands clearly indicate a switchport configuration, not a routed port.
✗It forces the phone to use CAPWAP before receiving power.Wrong answer — click to see why▾
Why this is wrong here
CAPWAP (Control and Provisioning of Wireless Access Points) is a protocol used for wireless LAN controller and access point communication, not for voice VLAN configuration. The voice VLAN feature is unrelated to CAPWAP.
★ When this WOULD be the correct answer
If the question were about the configuration of a wireless access point that requires a specific protocol for power delivery and management, such as CAPWAP, then this option could be correct. For example, a question might ask about the setup of a VoIP phone connected to a wireless network that utilizes CAPWAP for device management.
Why candidates choose this
The acronym 'CAPWAP' might be associated with Cisco's voice or wireless technologies, leading students to incorrectly link it to IP phone configuration.
✗It makes VLAN 150 the native VLAN on all trunks automatically.Wrong answer — click to see why▾
Why this is wrong here
The `switchport voice vlan` command only affects the specific access port where it is configured, not all trunk ports. The native VLAN on trunks is configured separately with `switchport trunk native vlan`.
★ When this WOULD be the correct answer
In a different question, if it asked about the behavior of a switch when configuring a trunk port with 'switchport trunk native vlan 150', this option would be correct as it would indicate that VLAN 150 is set as the native VLAN for all trunk links.
Why candidates choose this
Students may think that setting a voice VLAN on an access port automatically propagates to trunks, confusing the scope of the command with global or trunk-specific settings.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
Avoid confusing voice VLAN configurations with trunking or prioritization settings.
Trap categories for this question
Command / output trap
This is wrong because the command affects the edge port, not all trunks.
Detailed technical explanation
How to think about this question
In Cisco switching, a single physical switch port can carry traffic for both data and voice devices by using VLAN separation. The command 'switchport access vlan 20' assigns the port's default VLAN for data traffic, while 'switchport voice vlan 150' designates a separate VLAN specifically for voice traffic from IP phones. This design allows the IP phone to tag its voice packets with VLAN 150, while the connected workstation sends untagged data packets assigned to VLAN 20. The switch then segregates and forwards these traffic types appropriately within the network.
The switchport voice VLAN feature enables the switch to recognize voice traffic and prioritize it for quality of service (QoS) purposes, ensuring clear voice communication. The access VLAN remains the default VLAN for untagged frames, typically from a connected PC. This approach supports a common enterprise edge design where a single physical port supports both a phone and a PC, simplifying cabling and maintaining traffic separation without requiring the port to be configured as a trunk.
A common exam trap is confusing the voice VLAN configuration with trunk port behavior or routed interfaces. The voice VLAN command does not convert the port into a trunk or routed interface; it only tags voice traffic on an access port. Misunderstanding this can lead to incorrect assumptions about VLAN propagation or port roles. Practically, this design ensures that voice and data traffic coexist on one port but remain logically separated for security and QoS, which is essential in IP telephony deployments.
KKey Concepts to Remember
A switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port.
The 'switchport voice vlan' command designates a separate VLAN for tagged voice traffic from IP phones on the same physical port.
Voice VLANs enable traffic separation and prioritization of voice packets to maintain call quality in converged networks.
A single physical switch port can simultaneously support both voice and data devices by using access and voice VLANs.
The voice VLAN feature does not convert the port into a trunk or routed interface; it remains an access port with VLAN tagging for voice.
Cisco switches use the voice VLAN to identify and prioritize voice traffic without requiring complex trunk configurations on edge ports.
The access VLAN carries untagged frames typically from connected workstations, while the voice VLAN carries tagged frames from IP phones.
Proper VLAN separation on access ports prevents voice and data traffic from mixing, enhancing security and network performance.
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
A switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port.
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 200-301 question in full detail.
Review a switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port., then practise related 200-301 questions on the same topic to reinforce the concept.
Switching and Network Access — This question tests Switching and Network Access — A switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port..
What is the correct answer to this question?
The correct answer is: It separates voice and data traffic on the same edge port by assigning them to different VLANs. — The design purpose is to let the switch support a phone and an attached workstation on the same physical access port while placing their traffic into different VLANs. In practical terms, the phone can use the voice VLAN while the user's data traffic uses the access VLAN. This is a common enterprise edge design for IP telephony.
The key idea is role separation on one port, not trunking the port as a normal inter-switch link.
What should I do if I get this 200-301 question wrong?
Review a switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port., then practise related 200-301 questions on the same topic to reinforce the concept.
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?
A switchport configured with 'switchport access vlan' assigns untagged data traffic to a specific VLAN on an access port.
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 200-301 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 200-301 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.