EveryIPv6

using System;
using System.IO;
namespace EveryIPv6
{
    class Program
    {
        static void Main(string[] args)
        {
            using (StreamWriter sw = new StreamWriter("dump.txt"))
                for (ulong u1 = ulong.MinValue; u1 <= ulong.MaxValue; u1++)
                    for (ulong u2 = ulong.MinValue; u2 <= ulong.MaxValue; u2++)
                    {
                        for (byte b = 0; b < 4; b++)
                            sw.Write(((u1 >> ((3 - b) * 16)) & 0xFFFF).ToString("X4") + ":");
                        for (byte b = 0; b < 4; b++)
                            sw.Write(((u2 >> ((3 - b) * 16)) & 0xFFFF).ToString("X4") + (b == 3 ? '\n' : ':'));
                    }
        }
    }
}