100-150 Question 187
Single answerA network administrator has configured a switch with multiple VLANs to segment network traffic. However, users in one VLAN cannot communicate with users in another VLAN. What could be the reason for this issue?
- A
Switches do not support inter-VLAN communication by default.
- B
The VLANs are configured incorrectly on the switch.
- C
A router or Layer 3 device is required for inter-VLAN communication.
- D
The switch ports are operating in trunk mode instead of access mode.
Show answer and explanation
Correct answer: C
Explanation
Switches operate at Layer 2 and can segment traffic into VLANs, but they cannot route traffic between VLANs. To enable communication between VLANs, a router or Layer 3 switch must be used to route the traffic. This is a key concept in understanding basic switching and VLAN functionality.
- A. Incorrect.
Correct: By default, switches operate at Layer 2 and do not support inter-VLAN communication, which requires Layer 3 functionality.
- B. Incorrect.
Incorrect: This is unlikely the issue since VLANs are operational and properly segmenting traffic.
- C. Correct.
Correct: Inter-VLAN communication requires routing, which can only be achieved through a router or Layer 3 switch.
- D. Incorrect.
Incorrect: Trunk mode is used to carry multiple VLANs on a single link and does not prevent inter-VLAN communication if routing is configured.