Server.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using System.Net.Sockets;

namespace NetApp001
{
    class Program
    {
        static void Main(string[] args)
        {

            Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            IPEndPoint mySelf = new IPEndPoint(IPAddress.Parse("192.168.100.209"), 5000);
            socket.Bind(mySelf);

            while (true)
            {
                byte[] data = new byte[4096];
                EndPoint sender = new IPEndPoint(0, 0);
                int rlen = socket.ReceiveFrom(data, ref sender);

                if (rlen > 0)
                {
                    Console.WriteLine(Encoding.ASCII.GetString(data, 0, rlen));
                }
            }

        }
    }
}