Ping is the name of a computer network tool used on Internet protocol suite networks (such as the Internet). It provides a basic test of whether a particular Server is operating properly and is reachable on the network from the testing host. It also provides estimates of the round-trip time and packet loss rate between the hosts. It works by sending ICMP echo request packets to the target host and listening for replies (ICMP echo response packets); its operation is analogous to active sonar in submarine, in which an operator issues a pulse of energy (a network packet) at the target, which then bounces from the target and is then received by the operator, hence the name.

The author of the tool, Mike Muuss, named it after the pulses of sound made by a sonar. (Later David L. Mills provided a backronym, Packet Internet Grouper (Groper) [http://ftp.arl.mil/~mike/ping.html])

The usefulness of ping in assisting the diagnosis of Internet connectivity issues was impaired from late in 2003, when a number of Internet Service Providers filtered out ICMP Type 8 (echo request) messages at their network boundaries. Computer worm such as Welchia flooded the Internet with ping requests as they sought to locate new Computers to infect, causing problems to Routers across the Internet.

Related network tools include Traceroute and, on Windows NT-based systems, pathping.

= Sample ping output =

The output of ping, and its cousins, generally consists of the packet size used, the Server queried, the ICMP sequence number, the time to live, and the round-trip time, with all times given in milliseconds, and times below 10 milliseconds often having low accuracy.

Below is a sample output where we ping the wikipedia.com server: $ ping -c 5 wikipedia.com PING wikipedia.com (130.94.122.195): 56 data bytes 64 bytes from 130.94.122.195: icmp_seq=0 ttl=235 time=284.3 ms 64 bytes from 130.94.122.195: icmp_seq=1 ttl=235 time=292.9 ms 64 bytes from 130.94.122.195: icmp_seq=2 ttl=235 time=289.7 ms 64 bytes from 130.94.122.195: icmp_seq=3 ttl=235 time=282.4 ms 64 bytes from 130.94.122.195: icmp_seq=4 ttl=235 time=272.0 ms --- The above sample is typical of ping on an operating system with a System V lineage; on Microsoft Windows, ping always sends only 4 ping packets. On a system with a BSD Unix lineage, ping traditionally only answers whether a host is alive or not, but modern systems may provide a more System Vlike output as shown above.

= Interpretation of ping times =

To have some comparison for internet ping times, consider that the shortest possible ping to the other side of our planet is 85 ms. That is because 85 ms is the time the light needs to travel to the other side and back in a straight line through the earth. No signal can travel faster than light. The shortest possible ping would be 133 ms if we avoided a subterranean route. In practice, the actual ping is always higher, 333 ms not being unusual.

= Pinging Yahoo.com =

Since 1990s many people ping yahoo.com when their internet connection seems slow or dead. This habit appears to be quite common and probably emerged in early 1990s. Many Internet Service Provider support technicians and simply tech-savvy individuals recommended pinging yahoo.com, creating this meme. It caught on, because in early 1990s Yahoo was the primary hub of useful information and the domain name was already well known.

Yahoo is still fondly remembered by many, ensuring that it remains the favourite ping target. However some people ping different servers, such as 4.2.2.2, their ISPs (aol.com), large news sites (cnn.com) or other search engines (av.com, google.com). Google has probably exceeded Yahoo as a popular ping target due to it s current level of popularity.

=Slang usage=

Players of multiplayer online video games often use the term ping to refer to the network latency seen between their computer and the game server (or another player). This could be reported as an averaged time in milliseconds, or more generally as low ping or high ping . This usage is common with players of a variety of First-person shooter and Real-time strategy games. In most cases, being a so-called low ping bastard is desirable because lower latency provides smoother gameplay by allowing more frequent updates of game data. In some cases, though, games seem to give unfair advantage to high-ping users, as in some iterations of the Half-Life engine.

In this sense, ping is conflated with lag – one may lag out due to high ping.

The method used by the game programmers to determine ping times will often not use the traditional ICMP echo request and reply packets, but instead piggyback the functionality onto existing game data packets (often using User Datagram Protocol).

=Slang usage (2)=

Slang term used in business referring to the practice of (usually) informally contacting multiple people in an organization to ferret differences in opinion with the intent to locate an attractive opinion (to the seeker) which may be misrepresented as fact. Example: Joe pinged Bill and Tom trying to get a better price. . Another form of usage is to describe an attempt to get a reply from someone. Example: I ll ping you again tomorrow if I don t hear from you tonight.

=Slang usage (3)=

Ping also refers to an ability in the . An example is the card Progidal Sorcerer, which taps to deal 1 damage. The slang way of saying that is I ping you for one from Tim (The nickname of the Sorcerer) ..

=Slang usage (4)=

Ping in IRC and other chat services is interpolated as Is there anybody in here and you may get a response such as Pong .

To ping out or go pingy is to suddenly go offline IRC on a network. This happens when someone disconnects abruptly from IRC without properly using the Quit fucntion. Moments later, the username will leave IRC.

= References =

=External links=