C#

using System;
using System.Net;
using System.Net.Sockets;

namespace multiCastSend
{
   class send
   {
      send(string mcastGroup, string port, string ttl, string rep) 
      {
         IPAddress ip;
         try 
         {
            Console.WriteLine("MCAST Send on Group: {0} Port: {1} TTL: {2}",mcastGroup,port,ttl);
            ip=IPAddress.Parse(mcastGroup);
				
            Socket s=new Socket(AddressFamily.InterNetwork, 
               SocketType.Dgram, ProtocolType.Udp);
				
            s.SetSocketOption(SocketOptionLevel.IP, 
               SocketOptionName.AddMembership, new MulticastOption(ip));

            s.SetSocketOption(SocketOptionLevel.IP, 
               SocketOptionName.MulticastTimeToLive, int.Parse(ttl));
			
            byte[] b=new byte[10];
            for(int x=0;x<b.Length;x++) b[x]=(byte)(x+65);

            IPEndPoint ipep=new IPEndPoint(IPAddress.Parse(mcastGroup),int.Parse(port));
				
            Console.WriteLine("Connecting...");

            s.Connect(ipep);

            for(int x=0;x<int.Parse(rep);x++) 
            {
               Console.WriteLine("Sending ABCDEFGHIJ...");
               s.Send(b,b.Length,SocketFlags.None);
            }

            Console.WriteLine("Closing Connection...");
            s.Close();
         } 
         catch(System.Exception e) { Console.Error.WriteLine(e.Message); }
      }

      static void Main(string[] args)
      {
         new send("224.5.6.7", "5000", "1", "2");
      }
   }
}

using System.Net.Sockets;
using System.Net;
using System;

namespace multiCastRecv 
{
   class recv 
   {

      recv(string mcastGroup, string port) 
      {
         Socket s=new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
			
         IPEndPoint ipep=new IPEndPoint(IPAddress.Any,int.Parse(port));
         s.Bind(ipep);
			
         IPAddress ip=IPAddress.Parse(mcastGroup);

         s.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership, new MulticastOption(ip,IPAddress.Any));

         while(true) 
         {
            byte[] b=new byte[10];
            Console.WriteLine("Waiting for data..");
            s.Receive(b);
            string str = System.Text.Encoding.ASCII.GetString(b,0,b.Length);
            Console.WriteLine("RX: " + str.Trim());
         }
         //s.Close();
      }

      public static void Main(string[] args) 
      {
         new recv("224.5.6.7","5000");
      }
   }
}