Example program to bind two sockets to same UDP port

gistfile1.cs

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

public class UdpSamePort
{
  public static void Main(string[] args)
  {
    IPEndPoint ipep = new IPEndPoint(IPAddress.Any, 9000);

    Socket udpSocket1 = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
    udpSocket1.Bind(ipep);

    Socket udpSocket2 = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

    // Uncomment this line causes the udpSocket2 bind to throw an exception complaining that the address is already in use.
    //udpSocket2.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, false);

    udpSocket2.Bind(ipep);
  }
}

This fails on Windows with the expected "Only one usage of each socket address is normally permitted" message. At least on Mono 3.2.8 this raises no error.