Which scan would be used to determine if a host responds to ICMP ECHO requests, indicating possible firewall filtering?

Which scan would be used to determine if a host responds to ICMP ECHO requests, indicating possible firewall filtering?

• A. ICMP address mask ping
• B. Angry IP Scanner
• C. ICMP ECHO ping scans
• D. UDP Ping Scan

Answer: (C)

The test is about using ICMP Echo to check reachability and whether ICMP traffic is allowed by a firewall. An ICMP ECHO ping scan sends an ICMP Echo Request to the target. If the host replies with an ICMP Echo Reply, you see evidence that the host is up and that ICMP ECHO traffic is not being blocked. If you get no reply, it often indicates that a firewall or ACL is filtering ICMP ECHO requests, even if the host is alive. This makes ICMP ECHO ping scans the direct method to determine if a host responds to ICMP ECHO traffic and to infer possible firewall filtering. In contrast, ICMP address mask ping uses a specific ICMP request that's rarely supported on modern devices, Angry IP Scanner is a general scanning tool that can perform ping sweeps but the underlying method is typically ICMP Echo, and UDP ping scans probe UDP ports, relying on different responses and not testing ICMP ECHO directly.

The test is about using ICMP Echo to check reachability and whether ICMP traffic is allowed by a firewall. An ICMP ECHO ping scan sends an ICMP Echo Request to the target. If the host replies with an ICMP Echo Reply, you see evidence that the host is up and that ICMP ECHO traffic is not being blocked. If you get no reply, it often indicates that a firewall or ACL is filtering ICMP ECHO requests, even if the host is alive. This makes ICMP ECHO ping scans the direct method to determine if a host responds to ICMP ECHO traffic and to infer possible firewall filtering.

In contrast, ICMP address mask ping uses a specific ICMP request that's rarely supported on modern devices, Angry IP Scanner is a general scanning tool that can perform ping sweeps but the underlying method is typically ICMP Echo, and UDP ping scans probe UDP ports, relying on different responses and not testing ICMP ECHO directly.