title: How do I force an iOS app to use 3G instead of WiFi?
body: <p>I want to use a messaging protocol that works fine over 3G, but not over some corporate firewalls. How can my app force the use of the cellular network when it fails to connect over WiFi even in the case that the WiFi network is reachable?</p>
  
  <p><strong>EDIT:</strong> After reading through the implementation of the Reachability class I remain unsure whether the two are indeed mutually exclusive. It could well be possible to discover both interfaces via <code>gethostbyname()</code>, which I might try just to see what comes out.</p>