Scan Types supported by Nmap (cont.)
¨UDP Scanning (-U)
–Sends a UDP packet to target ports to determine if a UDP service is listening
–If the target system returns an ICMP Port Unreachable message, the target port is closed. Otherwise, the target port is assumed to be open.
–Unreliable since there may be false positives
–Client program of discovered open port is used to verify service
¨Ping (-sP)
–Sends ICMP echo request packets to every machine on the target network, allowing for locating live hosts. This isn’t port scanning; it’s network mapping.
–Can use TCP packets instead of ICMP to conduct Ping sweep
¨