200-301 Question 172
Single answerA network engineer is tasked with configuring VLAN 10 to span across two switches (Switch1 and Switch2). The engineer has configured VLAN 10 on both switches and assigned ports to the VLAN. However, devices on VLAN 10 connected to Switch1 cannot communicate with devices on VLAN 10 connected to Switch2. What could be the issue?
- A
The trunk port between Switch1 and Switch2 is not configured or operational.
- B
VTP (VLAN Trunking Protocol) is not enabled on both switches.
- C
The VLAN 10 IP address subnet is mismatched between the devices on Switch1 and Switch2.
- D
Spanning Tree Protocol (STP) has blocked the VLAN 10 traffic on the trunk port.
Show answer and explanation
Correct answer: A
Explanation
For VLAN traffic to span multiple switches, a trunk port must be configured between the switches. Trunk ports carry traffic for multiple VLANs by tagging the frames with VLAN IDs. If the trunk port is not configured or operational, VLAN traffic cannot traverse between the switches, causing communication issues.
- A. Correct.
This is the correct answer. VLANs spanning multiple switches require a trunk port between the switches to carry VLAN-tagged traffic. If the trunk port is not configured or operational, VLAN 10 traffic will not be able to travel between the switches.
- B. Incorrect.
VTP is helpful for managing VLANs across multiple switches, but it is not necessary for VLAN communication as long as the VLAN is manually created on both switches.
- C. Incorrect.
IP addressing is irrelevant to VLAN layer 2 communication. VLANs operate at Layer 2 and do not rely on IP addresses unless routing is involved.
- D. Incorrect.
STP may block ports to prevent loops, but it does not selectively block traffic for specific VLANs unless there is a specific misconfiguration, which is not indicated in the scenario.