gistfile1.txt

using System;
using System.Net.Sockets;
using System.Threading.Tasks;

public class Program {
	public static void Main (string[] args)
	{
		Action<int> create_port = port => { var listener = TcpListener.Create (port); 							listener.Start(); };

		for (int x = 0; x < 10; x++) {
			var port = 1200 + x;
			Task.Run (() => create_port (port));
		}
		Console.ReadLine();
	}
}