Ping ist ein tool for analysis, that displays the availability of the destination host and the signal propagation delay to reach this host.
For this the tool sends several ICMP-Packages (echo request, „ping“) to the host, that should respond with the ICMP-Package (echoreply, „pong“) to show its availability.
Is the host not available, the responsible router responds with „network unreachable“ or „host unreachable“.
Please note, that a firewall can suppress the ICMP-response of your machine. The existence of your computer in the net is then harder to detect.
C:\>ping google.de Ping wird ausgeführt für google.de [209.85.229.104] mit 32 Bytes Daten: Antwort von 209.85.229.104: Bytes=32 Zeit=44ms TTL=54 Antwort von 209.85.229.104: Bytes=32 Zeit=44ms TTL=54 Antwort von 209.85.229.104: Bytes=32 Zeit=43ms TTL=54 Antwort von 209.85.229.104: Bytes=32 Zeit=43ms TTL=54 Ping-Statistik für 209.85.229.104: Pakete: Gesendet = 4, Empfangen = 4, Verloren = 0 (0% Verlust), Ca. Zeitangaben in Millisek.: Minimum = 43ms, Maximum = 44ms, Mittelwert = 43ms