easyMultiple Choice
350-401 Practice Question: The default native VLAN on a Cisco switch trunk…
What is the default native VLAN on a Cisco switch trunk port?
⚠ Common exam trap
Cisco often tests the misconception that the native VLAN is always VLAN 1 by default, but the trap is that candidates may confuse it with the management VLAN (also often VLAN 1) or assume that changing the native VLAN is required for trunking to work.
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
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VLAN 1
The default native VLAN on a Cisco switch trunk port is VLAN 1. The native VLAN is the VLAN that carries untagged traffic over a trunk link, and by default, all switch ports (including trunk ports) belong to VLAN 1. This is defined in the IEEE 802.1Q standard, which specifies that frames on the native VLAN are not tagged with a VLAN ID.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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VLAN 1
Why this is correct
VLAN 1 is the default native VLAN on all Cisco switches. When a port is configured as an access port or when a trunk is created without an explicit native VLAN assignment, VLAN 1 carries all untagged traffic for backward compatibility with legacy bridging. It is also part of the default VLAN list that cannot be deleted from a standard switch, making it the correct answer to any question asking for the default 802.1Q native VLAN.
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VLAN 0
Why it's wrong here
VLAN 0 is not a valid VLAN identifier in IEEE 802.1Q or Cisco IOS. The 802.1Q tag uses a 12-bit VLAN ID field, which allows values from 1 to 4094; the value 0 is reserved to indicate a priority-tagged frame (a frame with only a priority, no VLAN ID) and is never assigned as a native VLAN. Consequently, VLAN 0 cannot be configured or used as the default native VLAN on any Cisco switch.
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VLAN 1002
Why it's wrong here
VLAN 1002 is one of the four legacy default VLANs (1002–1005) reserved for FDDI and Token Ring, but it is not the native VLAN. Cisco switches automatically create these VLANs for backwards compatibility with older campus technologies, and they are not used as the untagged VLAN on an 802.1Q trunk. The default native VLAN is always VLAN 1, regardless of the presence of these reserved VLANs in the VLAN database.
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VLAN 4095
Why it's wrong here
VLAN 4095 is outside the valid VLAN ID range (1–4094) defined by IEEE 802.1Q. The maximum usable VLAN ID is 4094; VLAN 4095 is reserved for implementation-specific internal use, such as a system VLAN or for switch control plane traffic, and it cannot be assigned as a native VLAN. Since the default native VLAN must be a valid, user-configurable VLAN ID, VLAN 4095 is never the correct answer for this default.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.