200-301 Question 26
Single answerYou are troubleshooting a connectivity issue where a host endpoint in a corporate network cannot reach an external web server. The host is correctly assigned an IP address via DHCP, and it can ping other devices on the same subnet. Which of the following is the MOST likely cause of the issue?
- A
The host's default gateway is incorrectly configured or unreachable.
- B
The host's DNS server is incorrectly configured.
- C
The host's IP address is not part of the DHCP pool.
- D
The subnet mask on the host is incorrectly configured.
Show answer and explanation
Correct answer: A
Explanation
For a host to communicate with devices outside its local subnet, it relies on the default gateway. If the default gateway is incorrectly configured or unreachable, traffic destined for external networks will fail. Since the host can ping other devices on the same subnet, the issue is not related to the subnet mask but to the gateway configuration.
- A. Correct.
If the default gateway is incorrectly configured or unreachable, the host cannot communicate with devices outside its local subnet, such as an external web server.
- B. Incorrect.
An incorrectly configured DNS server would prevent the host from resolving domain names to IP addresses, but it would not prevent connectivity to external systems if their IP addresses are known. In this case, the question specifies a general connectivity issue.
- C. Incorrect.
If the host's IP address is not part of the DHCP pool, it would not receive an IP address via DHCP at all. This is not the issue here, as the host has an IP address and can ping other devices on the subnet.
- D. Incorrect.
An incorrect subnet mask could cause routing issues, but this is unlikely here because the host can communicate with other devices on the same subnet, indicating the subnet mask is correctly configured.