The ping (Packet Internet Groper) command is a common method for troubleshooting the accessibility of devices. It uses Internet Control Message Protocol (ICMP) echo requests and ICMP echo replies to determine if another device is alive. It also measures the amount of time it takes to receive a reply from the specified destination. The ping command is mostly used to verify IP connectivity between two endpoints which could be switch to switch, host to host, or host to switch. The reply packet tells if the host received the ping and the amount of time it took to return the packet.