title: SignalR websocket fails with unexpected response code 502 (IIS 8.5 / ARR 3.0)
body: <p>When trying to establish a web socked connection using SignalR I get an unexpected response error 502.</p>
  
  <p>IE 10 reports:
  'WebSocket Error: Incorrect HTTP response. Status code 502, Bad Gateway'</p>
  
  <p>Chrome reports:
  'WebSocket connection to 'wss://domain/root/signalr/connect?transport=webSockets&amp;client....' failed: Error during WebSocket handshake: Unexpected response code: 502'</p>
  
  <p>When I connect directly to the server, everything works as it should.</p>
  
  <p>I have spend about 3-4 days now searching for how to get SignalR 2.2.1 working with an IIS 8.5, in Windows Server 2012 R2, ARR 3.0. I am using SSL/https, I have sticky sessions configured, same machine key on all my back end servers.</p>
  
  <p>I have setup a test system, that has only a single server behind it, I have tried every suggestion that I can find but I still cant find a solution - or for that matter anyone indicating that they have successfully configured this even though Microsoft claim it is support "with no extra config".</p>
  
  <p>Can anyone point me towards a guide or reference for getting this working ?</p>
  
  <p>Can anyone confirm it even works - or that it does not work ?</p>