Ping is a popular TCP/IP network utility using the Internet Control Message Protocol (ICMP) to determine the availability and responsiveness of network hosts. A system administrator uses the Ping tool to see if a computer is operating as wells as if network connections are intact.

The Internet Control Message Protocol (ICMP) Echo function used by the Ping tools is detailed in RFC 792. A small packet is sent through the network to a particular IP address. This packet contains 64 bytes - 56 data bytes and 8 bytes of protocol reader information. The computer that sent the packet then waits/listens for a return packet. If the connections are good and the target computer is up, a good return packet will be received. PING can also tell the user the number of hops that lie between two computers and the amount of time it takes for a packet to make the complete trip. In addition, an administrator can use Ping to test out name resolution. If the packet bounces back when sent to the IP address but not when sent to the name, then the system is having a problem matching the name to the IP address.

Ping is a part of all Linux distributions, FreeBSD, NetBSD, OpenBSD, Solaris, all Unix variants and Windows 95/98/NT/2000/XP operating systems. FreeBSD also has a Ping command that uses the ICMP6 ECHO_REQUEST datagram (as opposed to standard ICMP ECHO_REQUEST packets) that is called Ping6.

Related Terms: ICMP, FreeBSD, NetBSD, OpenBSD

Reference Links: ftp.arl.mil/~mike/ping.html: The story of Ping