100-140 Question 205
Select 2A user reports that they cannot access any websites or external resources, but they can successfully communicate with devices on their local network. As part of your troubleshooting steps, you suspect an issue with the default gateway. Which of the following could be a likely cause of this problem?
- A
The default gateway IP address is incorrectly configured on the user's device.
- B
The default gateway device (e.g., router) is powered off or unresponsive.
- C
The subnet mask on the user's device is misconfigured.
- D
The user's device has a duplicate IP address on the network.
- E
The DNS server address on the user's device is configured incorrectly.
Show answer and explanation
Correct answers: A, B
Explanation
The default gateway serves as the device that routes traffic from a local network to external networks. If the default gateway IP address is incorrectly configured, or if the gateway device itself is unresponsive, the user's device will be unable to send traffic to external networks, causing the issue described in the scenario.
- A. Correct.
If the default gateway IP address is incorrectly configured, the user's device will not know where to send traffic destined for external networks, preventing access to websites or external resources.
- B. Correct.
If the default gateway device is powered off or unresponsive, it cannot route traffic from the local network to external networks, causing connectivity issues.
- C. Incorrect.
A misconfigured subnet mask could cause communication issues within the local network but would not directly affect the user's ability to access external resources if the default gateway is correctly configured.
- D. Incorrect.
A duplicate IP address can cause network conflicts and connectivity issues, but it is unrelated to the specific issue of accessing external resources through the default gateway.
- E. Incorrect.
An incorrectly configured DNS server address could cause issues resolving domain names (e.g., www.google.com), but it would not prevent communication with external resources if the user attempted to access them via their IP addresses.