CCNP Infrastructure Practice Question
A network administrator is configuring a Cisco switch to support a new wireless LAN controller (WLC) that requires the switch port to carry traffic for multiple VLANs. The WLC will be connected to a trunk port. Which command must be used to configure the switch port as a trunk?
⚠ Common exam trap
It's easy for candidates to confuse the command that sets the encapsulation with the command that actually enables trunking mode, or thinking that disabling DTP is sufficient.
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 trunk
To configure a switch port as a trunk, the command 'switchport mode trunk' must be used. This enables the port to carry traffic for multiple VLANs using 802.1Q encapsulation. While other commands like 'switchport trunk encapsulation dot1q' may be required on some platforms, the essential command to set the mode is 'switchport mode trunk'. This is a fundamental configuration for connecting devices that need multiple VLANs, such as a WLC.
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 nonegotiate
Why it's wrong here
The command 'switchport nonegotiate' disables Dynamic Trunking Protocol (DTP) negotiation on the port. It is used to prevent the port from sending DTP frames, but it does not configure the port as a trunk. It is typically used after setting the port to trunk mode to avoid negotiation. This command alone does not enable trunking.
- ✓
switchport mode trunk
Why this is correct
The command 'switchport mode trunk' configures the interface to operate as a trunk, allowing it to carry traffic for multiple VLANs. This is necessary for connecting a WLC that needs to support multiple VLANs. It is the standard command to set a port to trunk mode on Cisco switches, enabling 802.1Q encapsulation.
- ✗
switchport trunk encapsulation dot1q
Why it's wrong here
The command 'switchport trunk encapsulation dot1q' sets the trunk encapsulation to 802.1Q, but it does not enable trunking itself. It is used in conjunction with 'switchport mode trunk' on switches that support multiple encapsulation types. Without setting the mode to trunk, the port will not operate as a trunk, so this command alone is insufficient.
- ✗
switchport mode access
Why it's wrong here
The command 'switchport mode access' configures the port as an access port, which can only carry traffic for a single VLAN. This is not suitable for a WLC that requires multiple VLANs. Access mode is used for end devices like PCs or printers, not for trunk connections to other switches or controllers.
Visual reference
About these practice questions
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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.