Get IPAddresses of all the systems connected to a website

protected void Page_Load(object sender, EventArgs e) 

    {        

   string myExternalIP;   

   string strHostName = System.Net.Dns.GetHostName(); 

      string clientIPAddress = System.Net.Dns.GetHostAddresses(strHostName).GetValue(0).ToString();   

   string clientip = clientIPAddress.ToString();  

   System.Net.HttpWebRequest request = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create("https://www.google.co.in/webhp?hl=en&sa=X&ved=0ahUKEwj1lsmrxdPTAhXFL48KHWLaD90QPAgD/xml/");         

    request.UserAgent = "User-Agent: InternetExplorer/4.0(compatible;MSIE" + "6.0;Windows NT 5.1;sv1;.NET CLR 1.1.4322;.NET CLR 2.0.50727)";  

    request.Method = "GET";      

       //request.Credentials = CredentialCache.DefaultCredentials;    

         HttpWebResponse response = (HttpWebResponse)request.GetResponse();    

         StreamReader reader = new StreamReader(response.GetResponseStream());   

          { 

                myExternalIP = reader.ReadToEnd();    

             reader.Close();   

          }    

         TextBox1.Text = myExternalIP.ToString();    

       }      

   private DataTable GetLocation(string ipaddress)     

    {  

           WebRequest rssReq = WebRequest.Create("https://www.google.co.in/webhp?hl=en&sa=X&ved=0ahUKEwj1lsmrxdPTAhXFL48KHWLaD90QPAgD/xml/" + ipaddress);         

    WebProxy px = new WebProxy("https://www.google.co.in/webhp?hl=en&sa=X&ved=0ahUKEwj1lsmrxdPTAhXFL48KHWLaD90QPAgD/xml/" + ipaddress, true);      

       rssReq.Proxy = px; 

            rssReq.Timeout = 2000;    

         try    

         { 

                WebResponse rep = rssReq.GetResponse();     

            XmlTextReader xtr = new XmlTextReader(rep.GetResponseStream());   

              DataSet ds = new DataSet();     

            ds.ReadXml(xtr);       

          return ds.Tables[0];     

        }  

           catch   

          {     

            return null;    

         }  

      }