Hi, 

this is what I've done in a project: 

 public IPAddress GetIPAddress()
        {
            var request = System.Web.HttpContext.Current.Request;

            string ipString;
            if (String.IsNullOrEmpty(request.ServerVariables["HTTP_X_FORWARDED_FOR"]))
            {
                ipString = request.ServerVariables["REMOTE_ADDR"];
            }
            else
            {
                ipString = request.ServerVariables["HTTP_X_FORWARDED_FOR"].Split(",".ToCharArray(), StringSplitOptions.RemoveEmptyEntries)
                    .FirstOrDefault();
            }

            IPAddress result;
            if (!IPAddress.TryParse(ipString, out result))
            {
                result = IPAddress.None;
            }

            return result;
        }

Then, later by using episervers geolocation (maxmind) api, 

var prov = Geolocation.Provider;
var result = prov.Lookup(ipAddress);

Hope it works.

I got a point in the right direction and the solution was pretty simple

public static List<VisitorGroup> GetUserVisitorGroups()
        {
            var visitorGroupHelper = new VisitorGroupHelper();
            var visitorGroups = new VisitorGroupStore();
            IEnumerable<VisitorGroup> groups = visitorGroups.List();

            var userVisitorGroups = new List<VisitorGroup>();

            foreach (var group in groups)
            {
                if (visitorGroupHelper.IsPrincipalInGroup(Thread.CurrentPrincipal, group.Name, new HttpContextWrapper(HttpContext.Current)))
                {
                    userVisitorGroups.Add(group);
                }
            }
            return userVisitorGroups;
        }

I then compared the groups with the  ACL key on the page(i set the visitor group as authorized to view the page)