100-150 Question 226
Single answerA network technician is troubleshooting connectivity to a web server. They issue a 'ping' command to the server's IP address, but the requests time out. The technician then uses 'tracert' (or 'traceroute') and sees that packets stop at a specific hop. The web server is confirmed to be online and reachable from other devices on the network. What is the most likely cause of this issue?
- A
A firewall is blocking ICMP traffic to or from the web server.
- B
The DNS server is not resolving the web server's hostname.
- C
The web server is configured with an incorrect default gateway.
- D
The client device has an invalid IP address configuration.
Show answer and explanation
Correct answer: A
Explanation
The ping command relies on ICMP (Internet Control Message Protocol) to send echo requests and receive replies. If a firewall is blocking ICMP traffic, the ping will fail, even if the target server is online. Similarly, tracert (or traceroute) uses ICMP to trace the path, and a firewall could block packets at a specific hop. Since the server is confirmed to be online and accessible from other devices, the most logical explanation is that a firewall is blocking ICMP traffic.
- A. Correct.
Correct. Firewalls often block ICMP traffic, which affects tools like 'ping' and 'tracert/traceroute'. This is likely the issue since the server is confirmed to be online and accessible from other devices.
- B. Incorrect.
Incorrect. DNS issues would prevent hostname resolution, but the technician is using the IP address directly in the ping command.
- C. Incorrect.
Incorrect. An incorrect default gateway on the server would affect all connectivity, not just ICMP traffic, and the server is confirmed to be reachable from other devices.
- D. Incorrect.
Incorrect. An invalid IP address on the client device would likely result in no connectivity at all, but the 'tracert' output shows progress up to a specific hop.