using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class MainClass
{
public static void Main()
{
int receivedDataLength;
byte[] data = new byte[1024];
IPEndPoint ip = new IPEndPoint(IPAddress.Any, 9999);
Socket socket = new Socket(AddressFamily.InterNetwork,SocketType.Dgram, ProtocolType.Udp);
socket.Bind(ip);
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
EndPoint Remote = (EndPoint)(sender);
while(true)
{
data = new byte[1024];
receivedDataLength = socket.ReceiveFrom(data, ref Remote);
Console.WriteLine(Encoding.ASCII.GetString(data, 0, receivedDataLength));
socket.SendTo(data, receivedDataLength, SocketFlags.None, Remote);
}
}
}