Network_Manager.Gadget.ControlPanel.Routes.SavedRoutes.UnloadForm.ValidateConfigs C# (CSharp) Method

        private bool ValidateConfigs()
        {
            IPAddress ipAddress = new IPAddress(0);
            if (unloadIPv4 > 0 && NotActiveIPv4Routes > 0 && defaultInterfaceMode.SelectedIndex == 0 ||
                unloadIPv4 > 0 && defaultInterfaceMode.SelectedIndex == 1)
            {
                if (defaultIPv4Interface.SelectedIndex == -1)
                {
                    tabControl1.SelectTab(0);
                    new BalloonTip("Information", "Select the route's default IPv4 interface", defaultIPv4Interface, BalloonTip.ICON.INFO);
                    return false;
                }
                if (defaultIPv4GatewayMode.SelectedIndex != 3)
                {
                    string ipv4Gateway = defaultIPv4Gateway.Text;
                    if (ipv4Gateway == "")
                        ipv4Gateway = "0.0.0.0";
                    if (!IPAddress.TryParse(ipv4Gateway, out ipAddress) ||
                    ipAddress.AddressFamily != System.Net.Sockets.AddressFamily.InterNetwork ||
                    Environment.OSVersion.Version.CompareTo(new Version("6.0")) > -1 && IP.CheckIfSameNetwork(ipv4Gateway, "0.0.0.0", "255.0.0.0") && !IP.CheckIfSameNetwork(ipv4Gateway, "0.0.0.0", "255.255.255.255") ||
                    Environment.OSVersion.Version.CompareTo(new Version("6.0")) < 0 && IP.CheckIfSameNetwork(ipv4Gateway, "0.0.0.0", "255.255.255.255") ||
                    IP.CheckIfSameNetwork(ipv4Gateway, "224.0.0.0", "224.0.0.0") ||
                    IP.CheckIfSameNetwork(ipv4Gateway, "240.0.0.0", "240.0.0.0"))
                    {
                        tabControl1.SelectTab(0);
                        new BalloonTip("Warning", "Invalid IPv4 gateway address", defaultIPv4Gateway, BalloonTip.ICON.WARNING);
                        return false;
                    }
                    defaultIPv4Gateway.Text = ipv4Gateway;
                }
            }
            if (unloadIPv6 > 0 && NotActiveIPv6Routes > 0 && defaultInterfaceMode.SelectedIndex == 0 ||
                unloadIPv6 > 0 && defaultInterfaceMode.SelectedIndex == 1)
            {
                if (defaultIPv6Interface.SelectedIndex == -1)
                {
                    tabControl1.SelectTab(1);
                    new BalloonTip("Information", "Select the route's default IPv6 interface", defaultIPv6Interface, BalloonTip.ICON.INFO);
                    return false;
                }
                if (defaultIPv6GatewayMode.SelectedIndex != 3)
                {
                    string ipv6Gateway = defaultIPv6Gateway.Text;
                    if (ipv6Gateway == "")
                        ipv6Gateway = "0.0.0.0";
                    if (!IP.ValidateIPv6(ref ipv6Gateway))
                    // && !Regex.IsMatch(gateway, @"^(::1|::)$") && IPAddress.TryParse(gateway, out ipAddress) && ipAddress.AddressFamily != System.Net.Sockets.AddressFamily.InterNetworkV6)
                    {
                        tabControl1.SelectTab(1);
                        new BalloonTip("Warning", "Invalid IPv6 gateway address", defaultIPv6Gateway, BalloonTip.ICON.WARNING);
                        return false;
                    }
                    defaultIPv6Gateway.Text = ipv6Gateway;
                }
            }

            return true;
        }