Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A switch port is configured with `switchport voice vlan 150` and `switchport access vlan 20`. Which statement best explains the design purpose?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
It separates voice and data traffic on the same edge port by assigning them to different VLANs.
This is correct because that is the classic voice-VLAN access-port design.
B
Distractor review
It turns the port into a routed WAN interface.
This is wrong because the configuration is for a switched access/voice-port role.
C
Distractor review
It forces the phone to use CAPWAP before receiving power.
This is wrong because CAPWAP is unrelated here.
D
Distractor review
It makes VLAN 150 the native VLAN on all trunks automatically.
This is wrong because the command affects the edge port, not all trunks.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is assuming that configuring 'switchport voice vlan' turns the port into a trunk or routed interface. Candidates might mistakenly believe that the voice VLAN command automatically makes VLAN 150 the native VLAN on all trunks or that it forces the port to behave like an inter-switch link. However, this command only applies to an access port connected to an IP phone and a workstation, separating voice and data traffic on that single port. Misinterpreting this can lead to incorrect VLAN designs and exam answer choices.
Technical deep dive
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.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
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Question 5
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Question 6
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FAQ
Questions learners often ask
What does this 200-301 question test?
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?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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