100-150 Question 220
Single answerA network administrator asks you to troubleshoot a connectivity issue between a workstation and a web server. You decide to use diagnostic commands. After running the 'ping' command to the server's IP address, you receive the following output:
'Pinging 192.168.1.10 with 32 bytes of data: Request timed out. Request timed out. Request timed out. Request timed out.'
What could be the most likely reason for this result?
- A
The web server is down or not responding.
- B
The workstation is using an incorrect subnet mask.
- C
The web server's DNS record is misconfigured.
- D
The firewall between the workstation and the web server is blocking ICMP traffic.
Show answer and explanation
Correct answer: D
Explanation
The 'ping' command relies on ICMP (Internet Control Message Protocol) to test connectivity. If ICMP traffic is blocked by a firewall or other security mechanism, the 'ping' command will fail with 'Request timed out' messages, even if the destination server is online and accessible via other protocols. This makes option 4 the most likely explanation.
- A. Incorrect.
While the web server being down is possible, it is not the most likely reason for the failure of the 'ping' command. A down server would typically result in no response, but ICMP traffic could also be blocked by network configurations.
- B. Incorrect.
An incorrect subnet mask on the workstation would likely cause local network issues, but it would not specifically result in 'Request timed out' errors for ICMP traffic alone.
- C. Incorrect.
A misconfigured DNS record would prevent hostname resolution, but the question specifies that you are pinging the server's IP address directly. Therefore, DNS is not relevant in this scenario.
- D. Correct.
If a firewall or security rule is blocking ICMP traffic, the 'ping' command will fail and result in 'Request timed out' messages, even if the server itself is up and reachable for other protocols.