问题：

    本机发送UDP数据，单给本机发送，那本机就接收不到，不管是```127.0.0.1```还是我本机的局域网ip，就是不行，但是给其他机子发送，带上本机的地址，那就可以接收到。

都可以收到的代码

        UdpClient udp = null;
        private void ReceiveMsg()
        {
            udp = new UdpClient(35796, AddressFamily.InterNetwork);
            Thread thread = new Thread(HandleUdpMsg);
            thread.IsBackground = true;
            IsHandle = true;
            thread.Start();
        }

        private void HandleUdpMsg()
        {
            while (IsHandle)
            {
                IPEndPoint endPoint = null;
                byte[] buffer = udp.Receive(ref endPoint);
                string content = Encoding.UTF8.GetString(buffer);
                chatContentText.AppendText(endPoint.Address + ":\t" + content);
            }
        }

单给本机发送接收不到的代码，但是带上其他机器就可以接收到的代码

        ConcurrentQueue<byte[]> udpQueue = new ConcurrentQueue<byte[]> ();
        private static void ReceiveMessage(object obj)
        {
            // 获取网络设备  
            var devices = CaptureDeviceList.Instance;
            //从列表中提取数据
            ICaptureDevice device = devices[0];
            int readTimeoutMilliseconds = 1000;
            //打开捕获设备
            device.Open(DeviceMode.Promiscuous, readTimeoutMilliseconds);

            device.Filter = "ip and udp";

            Packet packet = null;
            string port = string.Empty;
            string s = string.Empty;


            while (true)
            {
                try
                {

                    if (device != null)
                    {
                        var rawCaptire = device.GetNextPacket();
                        if (rawCaptire != null)
                        {
                            try
                            {
                                packet = Packet.ParsePacket(rawCaptire.LinkLayerType, rawCaptire.Data);
                            }
                            catch (Exception)
                            {

                                throw;
                            }
                            var udp = packet.Extract(typeof(UdpPacket));

                            var Address = UdpPacket.GetEncapsulated(packet);

                            port = Address.DestinationPort.ToString();
			if(port == "35796"){
					udpQueue.Enqueue(udp.PayloadData);			
                            }
				}}
                }
                catch (Exception ex)
                {
                    continue;
                }
            }
        }

发送端代码

        private void MsgSendBtn_Click(object sender, EventArgs e)
        {
            string text = sendMsgText.Text;
            if (string.IsNullOrEmpty(text))
            {
                return;
            }
            byte[] bytes = Encoding.UTF8.GetBytes(text + "\n");
            IPAddress ip = IPAddress.Parse("172.16.20.110");
            int port = 35796;
            IPEndPoint remote = new IPEndPoint(ip, port);
            UdpClient udp = new UdpClient();
            udp.Connect(remote);
            int sendLength = udp.Send(bytes, bytes.Length);
            SendResult.Text = "已向\t" + ip.ToString() + "\t发送\t" + sendLength + "\t字节。";
            chatContentText.AppendText("我："+text + "\n");
            sendMsgText.Clear();
        }