Клиент-серверное приложение

public static string GetLocalIPAddress()
{
    var host = Dns.GetHostEntry(Dns.GetHostName());
    foreach (var ip in host.AddressList)
    {
        if (ip.AddressFamily == AddressFamily.InterNetwork)
        {
            return ip.ToString();
        }
    }
    throw new Exception("Сетевые карты не найдены!");
}

string Host = Dns.GetHostName();
string IP = Dns.GetHostAddresses(Host)[0].ToString();

void Start(){
            localIp = InitLocalIp();
            Socket sock = new Socket(AddressFamily.InterNetwork,
                SocketType.Dgram, ProtocolType.Udp);
            IPEndPoint iep = new IPEndPoint(IPAddress.Any, 1556);
            sock.Bind(iep);
            EndPoint ep = (EndPoint)iep;
            Debug.Log("Ready to receive...");
 
            byte[] data = new byte[1024];
            int recv = sock.ReceiveFrom(data, ref ep);
            string stringData = Encoding.ASCII.GetString(data, 0, recv);
            Debug.Log($"received: {stringData}  from: {ep}");
 
            sock.SendTo(Encoding.ASCII.GetBytes(localIp), ep);
}
    static string InitLocalIp()
    {
        string Host = Dns.GetHostName();
        string IP = Dns.GetHostAddresses(Host)[0].ToString();
        return IP;
    }

            UdpClient udp = new UdpClient();
            int GroupPort = 1556;
            IPEndPoint groupEP = new IPEndPoint(IPAddress.Broadcast, GroupPort);    //Parse("255.255.255.255")
            string str4 = "Is anyone out there?";
            byte[] sendBytes4 = Encoding.ASCII.GetBytes(str4);
            udp.Send(sendBytes4, sendBytes4.Length, groupEP);
            byte[] receiveBytes = udp.Receive(ref groupEP);
            string returnData = Encoding.ASCII.GetString(receiveBytes);
            Debug.Log("Response: " + returnData);