350-401 Infrastructure Practice Question
A network administrator is configuring a Cisco switch port that connects to an IP phone and a PC. The phone must tag voice traffic with VLAN 200, and the PC must send untagged traffic on VLAN 100. Which configuration is required on the switch port?
⚠ Common exam trap
The trap here is selecting a trunk configuration when the voice VLAN feature on an access port is the intended solution for a phone and PC on the same switch port.
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 100; switchport voice vlan 200
The correct configuration uses an access port with a data VLAN and a voice VLAN. The voice VLAN feature allows the switch to instruct the IP phone to tag voice traffic with the specified VLAN, while the PC's untagged traffic is placed in the access VLAN. This provides separation of voice and data traffic and is the typical deployment for Cisco IP phones.
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 100; switchport voice vlan 200
Why this is correct
This configuration sets the port as an access port for data VLAN 100 and enables voice VLAN 200 for tagged voice traffic from the IP phone. The phone will tag voice frames with VLAN 200, while the PC sends untagged frames that are placed in VLAN 100. This is the standard Cisco IP phone configuration.
- ✗
switchport mode access; switchport access vlan 200; switchport voice vlan 100
Why it's wrong here
This reverses the VLAN assignments: data VLAN 200 and voice VLAN 100. The requirement states voice VLAN 200 and data VLAN 100, so this configuration is incorrect. The phone would tag voice traffic with VLAN 100, and the PC would be on VLAN 200, opposite of what is needed.
- ✗
switchport mode trunk; switchport trunk encapsulation dot1q; switchport trunk allowed vlan 100,200
Why it's wrong here
This creates a trunk that allows both VLANs, but it does not specify a voice VLAN. The IP phone would need to be manually configured to tag voice traffic, and the PC would need to tag data traffic or use the native VLAN. This is not the standard Cisco recommended configuration for an IP phone and PC on the same port.
- ✗
switchport mode trunk; switchport trunk native vlan 100; switchport trunk allowed vlan 200
Why it's wrong here
This configures a trunk port with native VLAN 100 and allows VLAN 200. While it would carry both VLANs, it is not the recommended method for connecting an IP phone and PC. A trunk port would require the PC to tag its traffic or use the native VLAN, which is less secure and not typical for this scenario.
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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.