/// <summary>
        /// updates active connection list in GUI
        /// </summary>
        private void updateActiveConnections()
        {
            //ipList = connector.GetActiveConnections();
            List <String> activeIpList = connector.GetActiveConnections();

            ipList = connector.GetValidConnections();
            if (ipList.Count != lbClientList.Items.Count)
            {
                if (!this.tabItemConnections.IsSelected)
                {
                    tabItemConnections.Background = new SolidColorBrush(Color.FromArgb(255, 200, 0, 0));
                }
            }
            List <String> tmpList = new List <String>();

            lbClientList.Items.Clear();
            foreach (String ip in ipList)
            {
                String tmp = "";
                foreach (String aip in activeIpList)
                {
                    if (aip.StartsWith(ip))
                    {
                        tmp = aip + "[ON]";
                        break;
                        //tmpList.Add(aip + "[ON]");
                    }
                }
                if (tmp == "")
                {
                    tmp = ip + "[OFF]";
                }
                tmpList.Add(tmp);
            }
            foreach (String ip in tmpList)
            {
                Label l = new Label();
                l.Content = ip;
                if (ip.EndsWith("[ON]"))
                {
                    l.Foreground = new SolidColorBrush(Color.FromArgb(255, 0, 255, 0));
                }
                lbClientList.Items.Add(l);
            }
            //}
        }