title: SignalR fails to send message to a group when running through LoadBalancer
body: <p>In order to send SignalR message to a specific user I create a Group for each user upon connection </p>
  
  <pre><code>public override Task OnConnected()
  {
      log.DebugFormat("Connected. Connection Id = {0} UserId = '{1}'", Context.ConnectionId, UserHelper.UserId);
      Groups.Add(Context.ConnectionId, UserHelper.UserId);
      return base.OnConnected();
  }
  </code></pre>
  
  <p>Now when a message comes in I send it a group in the following way:</p>
  
  <pre><code>var hubContext = GlobalHost.ConnectionManager.GetHubContext&lt;AlertsHub&gt;();
  
  foreach (var recipient in recipients)
  {
      hubContext.Clients.Group(recipient).broadcastAlertMessage("Group", msg);
  }
  </code></pre>
  
  <p>That <strong>works fine when deployed to a server</strong>, but for some reason not working when i access the server through our company load balancer (Citrix Netscaler SDX 11500) but eventually hitting the same sole box.</p>
  
  <p>There is no issue sending messages to all clients</p>
  
  <pre><code>hubContext.Clients.All.broadcastAlertMessage("All", msg);
  </code></pre>
  
  <p>Also i can keep the connection IDs internally and send messages to a specific client works</p>
  
  <pre><code>hubContext.Clients.Client(AlertsHub.UserToConnectionIdDict["admin"]).broadcastAlertMessage("trageted client", msg);
  </code></pre>
  
  <p>Why "Group" message doesn't work?</p>