title: AFNetworking reachability manager for domain - always reachable despite captive portal
body: <p>I'm using AFNetworking's reachability manager to monitor reachability for a specific domain, as illustrated below:</p>
  
  <pre><code>reachabilityManager = [AFNetworkReachabilityManager managerForDomain:@"www.xyz.com"];
  [reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
              switch (status) {
                  case AFNetworkReachabilityStatusReachableViaWWAN:
                  case AFNetworkReachabilityStatusReachableViaWiFi:
                      DLog(@"***became reachable***");
                      break;
                  case AFNetworkReachabilityStatusNotReachable:
                  default:
                      DLog(@"***became UNreachable***");
                      break;
              }
          }];
  [reachabilityManager startMonitoring];
  </code></pre>
  
  <p>It works well except when the device is connected to a captive portal/network with all other data disabled. For some reason the manager believes that the device is in a reachable state, despite the fact that the domain is in fact unreachable (if one were to input the corresponding URL in a browser, it redirects to the captive portal's sign-in page).</p>
  
  <p>Am I doing something wrong? If not, is there any way around this?</p>
  
  <p>Thanks!</p>