Which utility sends ICMP packets to a host?

Which utility sends ICMP packets to a host?

• A. nmap
• B. p0f
• C. --open
• D. ping(8)

Answer: (D)

Testing knowledge of which tool performs a basic reachability check by sending ICMP traffic. ICMP is used for diagnostics, and ping specifically sends an ICMP Echo Request to a target and waits for an Echo Reply, letting you confirm the host is reachable and gauge round-trip time. Other tools serve different purposes: nmap is primarily a port and service scanner (it can use ICMP as part of some scans, but not just to check reachability by default); p0f is a passive fingerprinting tool that analyzes observed traffic rather than sending probes; and the --open option is a filter for showing open ports, not a standalone utility. So ping is the one that directly sends ICMP packets to a host.

Testing knowledge of which tool performs a basic reachability check by sending ICMP traffic. ICMP is used for diagnostics, and ping specifically sends an ICMP Echo Request to a target and waits for an Echo Reply, letting you confirm the host is reachable and gauge round-trip time. Other tools serve different purposes: nmap is primarily a port and service scanner (it can use ICMP as part of some scans, but not just to check reachability by default); p0f is a passive fingerprinting tool that analyzes observed traffic rather than sending probes; and the --open option is a filter for showing open ports, not a standalone utility. So ping is the one that directly sends ICMP packets to a host.