Which scanning technique uses ICMP echo requests to determine which hosts are up?

Which scanning technique uses ICMP echo requests to determine which hosts are up?

• A. Traceroute
• B. Ping Sweep
• C. Port Scanning
• D. DNS Poisoning

Answer: (B)

ICMP echo requests are what the ping utility uses to check if a host is reachable. A ping sweep automates sending these ICMP Echo Requests across a range of IP addresses and records which ones respond with an Echo Reply, revealing which hosts are up. This technique is specifically for discovering live hosts quickly in a network. By contrast, traceroute sends probes with increasing TTL to map the path to a destination rather than just checking reachability; port scanning focuses on identifying open services on a host by probing ports; DNS poisoning involves corrupting or spoofing DNS responses, not determining whether hosts are online.

ICMP echo requests are what the ping utility uses to check if a host is reachable. A ping sweep automates sending these ICMP Echo Requests across a range of IP addresses and records which ones respond with an Echo Reply, revealing which hosts are up. This technique is specifically for discovering live hosts quickly in a network. By contrast, traceroute sends probes with increasing TTL to map the path to a destination rather than just checking reachability; port scanning focuses on identifying open services on a host by probing ports; DNS poisoning involves corrupting or spoofing DNS responses, not determining whether hosts are online.