What does the ping command primarily test?

The ping command primarily tests host reachability within a network, which is its primary function. When you execute a ping command, it sends Internet Control Message Protocol (ICMP) echo request packets to the specified IP address or hostname. If the target host is reachable, it responds with echo reply packets. This process helps determine if the host is online and able to respond over the network, effectively confirming the connectivity between the source and the destination.

While the command can provide additional insights, such as round-trip time and packet loss statistics, the core purpose is to check if a particular host can be reached across the network. This is crucial for troubleshooting network issues, as it helps identify whether a problem lies with the network connection or the specific host.