200-301 Question 187
Single answerYou are tasked with configuring interswitch connectivity between two switches, SwitchA and SwitchB, in a corporate network. Both switches are connected via their respective gigabit interfaces (Gig0/1). You need to ensure VLAN traffic can pass between the switches. After configuring the interfaces, you verify the setup but find that VLAN traffic is not flowing across the switches. Which configuration step is MOST likely missing?
- A
The interfaces on SwitchA and SwitchB need to be configured as trunk ports.
- B
The native VLAN must be assigned to the interfaces on both switches.
- C
A Layer 3 interface must be created to route traffic between VLANs.
- D
The STP (Spanning Tree Protocol) settings must be synchronized on both switches.
Show answer and explanation
Correct answer: A
Explanation
To enable VLAN traffic between switches, the connecting interfaces must be configured as trunk ports. Trunking allows traffic from multiple VLANs to pass through a single physical interface by tagging traffic with VLAN IDs. Without this configuration, the switches will not know how to handle VLAN-tagged traffic, resulting in communication failure. The other options either address different issues or are not relevant to this specific problem.
- A. Correct.
Correct. For VLAN traffic to pass between SwitchA and SwitchB, the connecting interfaces must be configured as trunk ports. Trunking allows multiple VLANs to traverse a single physical link.
- B. Incorrect.
Incorrect. While the native VLAN can be assigned to a trunk port, it is not required for VLAN traffic to flow across switches. The primary issue here relates to configuring trunking.
- C. Incorrect.
Incorrect. A Layer 3 interface is only required for inter-VLAN routing, not for interswitch VLAN traffic. The scenario does not mention routing between VLANs, so this option does not address the problem.
- D. Incorrect.
Incorrect. STP settings do not directly impact VLAN traffic flow between switches unless there is a loop or blocked port, which is not described in this scenario.