You can use the ping command to determine whether your system can communicate with a remote host. When you run the ping command, the ICMP protocol sends a datagram to the host that you specify, asking for a response. ICMP is the protocol that is responsible for error handling on a TCP/IP network. When you use the ping command, you can determine whether IP packets can be exchanged between your host and a specified remote host.
The following is the basic syntax of the ping command:
/usr/sbin/ping host [timeout]
where host is the name of the remote host. The optional timeout argument indicates the time (in seconds) for the ping command to continue trying to reach the remote host. The default is 20 seconds. For more information, see the ping (1M) man page.