350-401 Infrastructure Practice Question
A network engineer is configuring a Cisco Catalyst switch port that connects to an IP phone and a PC. The phone must tag its voice traffic with VLAN 200, and the PC must send untagged traffic that the switch places into VLAN 10. Which interface configuration accomplishes this?
⚠ Common exam trap
The trap here is assuming that a trunk is required to support a voice VLAN on an access port, when the switchport voice vlan command already handles the tagging.
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
✓
switchport mode access switchport access vlan 10 switchport voice vlan 200
The access-plus-voice configuration is the standard way to support an IP phone and a PC on one switch port. The access VLAN carries untagged PC traffic, and the voice VLAN carries 802.1Q-tagged phone traffic. This allows the phone to tag its own traffic while the PC sends untagged frames, and the switch classifies them into the correct VLANs without needing a trunk on the 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.
- ✓
switchport mode access switchport access vlan 10 switchport voice vlan 200
Why this is correct
This is the correct configuration. Setting the port to access mode with access VLAN 10 handles the untagged PC traffic, while the switchport voice vlan 200 command tells the switch to recognize 802.1Q-tagged frames for VLAN 200 as voice traffic from the attached IP phone. This is the standard Cisco IP telephony deployment model for a single physical port supporting both a phone and a PC.
- ✗
switchport mode trunk switchport trunk native vlan 10 switchport trunk allowed vlan 200
Why it's wrong here
This makes the port a trunk and restricts allowed VLANs to only 200, so untagged PC traffic in VLAN 10 would be dropped because VLAN 10 is not in the allowed list. Although the native VLAN is set to 10, the allowed VLAN list excludes it, so the PC cannot communicate. This is not the intended access-plus-voice design.
- ✗
switchport mode access switchport access vlan 200 switchport voice vlan 10
Why it's wrong here
This reverses the roles: the PC's untagged traffic would be placed into VLAN 200 and the phone's tagged traffic would be expected on VLAN 10. That contradicts the stated requirement that the phone uses VLAN 200 and the PC uses VLAN 10. The VLAN assignments must match the actual device traffic, so this configuration is incorrect for this scenario.
- ✗
switchport mode trunk switchport trunk encapsulation dot1q switchport trunk native vlan 200
Why it's wrong here
This creates a trunk with native VLAN 200, which would place untagged PC frames into VLAN 200 and also allow all VLANs by default. That does not meet the requirement of PC traffic in VLAN 10 and phone traffic in VLAN 200. Additionally, using a trunk instead of the access-plus-voice feature complicates the design unnecessarily.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
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.