|  |  | PING is a popular tool used to verify that a host is alive; it allows a hacker to start mapping a network. Web sites such as www.arin.net provide personal information about the owners of a network address. Port Scans tell the attacker what services are running on the remote host, revealing its operating system and exposing vulnerabilities. Packet sniffers analyze packets to discover their origins, destination address, and type of data. The telephone is commonly used to gain trust and extract valuable information.