private void CreateServer()
        {
            CoapConfig config = new CoapConfig();

            CoAPEndPoint endpoint = new CoAPEndPoint(0, config);

            _resource = new MulticastResource(MulticastTarget, MulticastResponse);
            _server   = new CoapServer();
            _server.Add(_resource);

            _server.AddEndPoint(endpoint);
            _server.Start();
            _serverPort = ((IPEndPoint)endpoint.LocalEndPoint).Port;

            endpoint.AddMulticastAddress(new IPEndPoint(multicastAddress3, _serverPort));
            endpoint.AddMulticastAddress(new IPEndPoint(multicastAddress4, _serverPort));
            endpoint.AddMulticastAddress(new IPEndPoint(multicastAddress, _serverPort + PortJump));
            endpoint.AddMulticastAddress(new IPEndPoint(multicastAddress2, _serverPort + PortJump));

            Resource r2 = new UnicastResource(UnicastTarget, UnicastResponse);

            _server.Add(r2);
        }