using System;

using System.Net;

public class Program

{

    public static void Main()

    {

        string remoteIpAddress = "7.7.7.7:123";

        string IPv4 = string.Empty;

        string IPv6 = string.Empty;

​

        if (remoteIpAddress.Contains(":"))

        {

            Console.WriteLine(remoteIpAddress);

            string[] cleanIpAddressremoteIpAddress = remoteIpAddress.Split(':');

            Console.WriteLine(remoteIpAddress.Split(':'));

        }

​

​

        if (string.IsNullOrEmpty(remoteIpAddress))

        {

            IPAddress address;

            if (IPAddress.TryParse(remoteIpAddress, out address))

            {

                switch (address.AddressFamily)

                {

                    case System.Net.Sockets.AddressFamily.InterNetwork:

                        IPv4 = address.ToString();

                        IPv6 = address.MapToIPv6().ToString();

                        break;

                    case System.Net.Sockets.AddressFamily.InterNetworkV6:

                        IPv4 = address.MapToIPv4().ToString();

                        IPv6 = address.ToString();

                        break;

                    default:

​

                        break;

                }

            }

        }

    }

}