100-150 Question 184
Single answerA network technician is troubleshooting connectivity issues in a small office network. The network consists of PCs connected to a Layer 2 switch, which is connected to a Layer 3 switch configured as the default gateway. One of the PCs can successfully communicate with other PCs on the same network but cannot access websites or communicate with devices on a remote network. What is the most likely issue?
- A
The Layer 2 switch is blocking traffic to the Layer 3 switch.
- B
The PC is configured with an incorrect default gateway.
- C
The Layer 3 switch does not have a route to the remote network.
- D
The PC's IP address is in a different subnet than the Layer 2 switch.
Show answer and explanation
Correct answer: B
Explanation
The default gateway is responsible for routing traffic from the local network to other networks, including remote networks. If the PC is configured with an incorrect default gateway, it will fail to send traffic to remote networks, even though local communication remains unaffected. This makes the incorrect default gateway the most plausible explanation for the described issue.
- A. Incorrect.
The Layer 2 switch only operates at Layer 2 of the OSI model and forwards traffic based on MAC addresses. It does not have the capability to block traffic to the Layer 3 switch in a way that would isolate the PC while allowing local communication.
- B. Correct.
An incorrect default gateway on the PC would prevent it from sending traffic to remote networks. Since the PC can communicate locally, this is the most likely cause of the issue.
- C. Incorrect.
While the absence of a route to the remote network on the Layer 3 switch could cause similar issues, it would affect all devices attempting to reach the remote network, not just a single PC.
- D. Incorrect.
The Layer 2 switch does not assign or manage IP addresses. If the PC’s IP address were in a different subnet, it would also be unable to communicate with other local PCs, which contradicts the scenario.