public static bool Echo(string ip)
{
    var udpClient = new UdpClient { Client = { ReceiveTimeout = 1000, SendTimeout = 1000 } };
    var localpt = new IPEndPoint(IPAddress.Parse(ip), 32887);
    var datagram = Encoding.ASCII.GetBytes("HELLO");

    try
    {
        udpClient.Send(datagram, datagram.Length, localpt);
        return Encoding.ASCII.GetString(udpClient.Receive(ref localpt)) == "HI";
    }

    catch
    {
        return false;
    }
}