there's not output when ip unreachable

[shyandsy]

How can i know that server is unreachable?

        p := fastping.NewPinger()
        ra, err := net.ResolveIPAddr("ip4:icmp", "111.111.111.1")
        if err != nil {
                panic(err)
        }
        p.AddIPAddr(ra)
        p.OnRecv = func(addr *net.IPAddr, rtt time.Duration) {
                fmt.Printf("IP Addr: %s receive, RTT: %v\n", addr.String(), rtt)
        }
        p.OnIdle = func() {
                fmt.Println("finish")
        }
        err = p.Run()
        if err != nil {
                fmt.Println(err)
        }

output

finish

in cmd