200-301 Question 170
Single answerYou are tasked with configuring VLAN 20 on two interconnected switches (Switch1 and Switch2) to allow devices in the same VLAN to communicate. After configuring VLAN 20 on both switches, you notice that devices in VLAN 20 on Switch1 cannot communicate with devices in VLAN 20 on Switch2. What is the most likely reason for this issue?
- A
The trunk port between Switch1 and Switch2 is not configured.
- B
VLAN 20 is not assigned to any ports on Switch2.
- C
The native VLAN on the trunk port is mismatched between Switch1 and Switch2.
- D
VLAN 20 is not created on Switch2.
Show answer and explanation
Correct answer: A
Explanation
For VLANs to span multiple switches, the link between the switches must be configured as a trunk port to allow tagged VLAN traffic to pass between the switches. Without this configuration, VLAN traffic will not traverse the switches, preventing communication between devices in the same VLAN on different switches.
- A. Correct.
This is the correct answer. For VLAN traffic to span multiple switches, the link between switches must be configured as a trunk port to allow VLAN traffic to pass through.
- B. Incorrect.
This is incorrect. Even if VLAN 20 is not assigned to any ports on Switch2, communication would still fail only for end devices on Switch2, not for devices between the two switches.
- C. Incorrect.
This is incorrect. A mismatched native VLAN would cause issues for untagged traffic, not for tagged VLAN traffic like VLAN 20.
- D. Incorrect.
This is incorrect. VLAN 20 must be created on Switch2 for devices on Switch2 to use it, but this does not explain why devices on Switch1 cannot communicate with devices on Switch2.