title: Uniquely identifying mobile devices over a network for webforms
body: <p>I'm designing a system for mobile devices that can be assigned only to one job at a time.  So I need to be able to know which mobile device is being used by accessing it's own unique static IP address or its device ID. I don't want to assign an ID myself for every machine that comes in which is why a static IP would work great.</p>
  
  <p>However, in trying to retrieve the client ip address I'm retrieving the wireless router's ip or some other ip which is not the mobile device's ip.</p>
  
  <p>I want to store that ip in a table and control which jobs are assigned to it. How can I accomplish this?</p>
  
  <p>I've tried the following but I'm getting the wireless ip: </p>
  
  <pre><code>   var hostEntry = Dns.GetHostEntry(Dns.GetHostName());
      var ip = (
                 from addr in hostEntry.AddressList
                 where addr.AddressFamily.ToString() == "InterNetwork"
                 select addr.ToString()
          ).FirstOrDefault();
  </code></pre>
  
  <p>I'd rather not set a cookie if there exists a better alternative.</p>
  
  <p>TIA!</p>