using System;

using System.Net;

public class Program

{

    public static void Main()

    {

        IPAddress ip = IPAddress.Parse("10.10.10.10");

        Console.WriteLine("IP: {0}, IPNumber {1}", ip, ConvertIPv4ToLong(ip.ToString()));

    }

                           public static long ConvertIPv4ToLong(string ipString)

        {

            IPAddress ipAddress = IPAddress.Parse(ipString);

            if (ipAddress.AddressFamily != System.Net.Sockets.AddressFamily.InterNetwork)

            {

                throw new InvalidOperationException("This method can only be used with an IPv4 address.");

            }

            Byte[] ipBytes = ipAddress.GetAddressBytes();

            return (long)ipBytes[0] << 24 | (long)ipBytes[1] << 16 | (long)ipBytes[2] << 8 | (long)ipBytes[3];

        }

}

​

​

​