ping命令是用来查看网络上另一个主机系统的网络连接是否正常的一个工具。ping命令的工作原理是：向网络上的另一个主机系统发送ICMP报文，如果指定系统得到了报文，它将把报文一模一样地传回给发送者，这有点象潜水艇声纳系统中使用的发声装置。-ping command is used to check on another network host system's network connection of a normal tool. Ping orders of the working principle is : on the network to another mainfr a me system to send ICMP message, if the designated system has been reported text, it will send the same message to send back to the sender, a bit like submarine sonar systems used in the devices.