Cliente Servidor UDP en C#

namespace PC1_Cliente
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btn_conectar_Click(object sender, EventArgs e)
        {
            UdpClient udpClient = new UdpClient();
            udpClient.Connect(IPAddress.Parse("127.0.0.1")/*txt_ip.Text*/, 8888);
            Byte[] sendBytes = Encoding.ASCII.GetBytes(txt_msg.Text);
            udpClient.Send(sendBytes, sendBytes.Length);
        }
    }
}

/* ------------------------------------------------------------------------- */

namespace PC2_Servidor
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            lb_pantalla.Items.Add("Esperando.....");
            //serverThread();
            
        }
        public void serverThread()
        {
            UdpClient udpClient = new UdpClient(8888);
            while (true)
            {
                IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1")/*Any*/, 0);
                Byte[] receiveBytes = udpClient.Receive(ref RemoteIpEndPoint);
                string returnData = Encoding.ASCII.GetString(receiveBytes);
                lb_pantalla.Items.Add(RemoteIpEndPoint.Address.ToString() + ":" + returnData.ToString());
            }
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            Thread thdUDPServer = new Thread(new
            ThreadStart(serverThread));
            thdUDPServer.Start();
        } 
    }
}