ping is probably the most basic TCP/IP command line tool. Its main purpose is to determine whether you can reach another computer from your computer. It uses Internet Control Message Protocol (ICMP) to send mandatory ECHO_REQUEST datagrams to the specified host computer. When the reply is received back from the host, the ping command displays how long it took to receive the response.
You can specify the host to ping by using an IP address, as in this example:
C:>ping 192.168.168.10
Pinging 192.168.168.10 with 32 bytes of data:
Reply from 192.168.168.10: bytes=32 time<1ms TTL=128
Reply from 192.168.168.10: bytes=32 time<1ms TTL=128
Reply from 192.168.168.10: bytes=32 time<1ms TTL=128
Reply from 192.168.168.10: bytes=32 time<1ms TTL=128
Ping statistics for 192.168.168.10:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms
C:>
By default, the ping command sends four packets to the specified host. It displays the result of each packet sent. Then it displays summary statistics: how many packets were sent, how many replies were received, the error loss rate, and the approximate round-trip time.
You can also ping by using a DNS name, as in this example:
C:>ping www.lowewriter.com
Pinging lowewriter.com [209.68.34.15] with 32 bytes of data:
Reply from 209.68.34.15: bytes=32 time=84ms TTL=53
Reply from 209.68.34.15: bytes=32 time=84ms TTL=53
Reply from 209.68.34.15: bytes=32 time=84ms TTL=53
Reply from 209.68.34.15: bytes=32 time=84ms TTL=53
Ping statistics for 209.68.34.15:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 84ms, Maximum = 84ms, Average = 84ms
C:>
The ping command uses a DNS query to determine the IP address for the specified host, and then pings the host based on its IP address.
The ping command has a number of other switches that you’ll use rarely, if ever. Some of these switches are available only for some operating systems. To find out which switches are available for your version of Ping, type ping /? (Windows) or man ping (Unix/Linux).
You can find a very interesting story about the creation of the ping command written by the command’s author, Mike Muus, at his website at Mike Ping. (Sadly, Mr. Muus was killed in an automobile accident in November of 2000.)
