Cross Domain Negotiation request error with SignalR

Question

I have an ASP.NET Web Api project in which SignalR has been implemented. In Stratup class I use CorsOptions.AllowAll. In WebApiConfig class I also use EnableCorsAttribute("", "", "*"). I published this Web Api project in a server location (http://192.168.9.6:3030). But while trying to connect using $.hubConnection("http://192.168.9.6:3030/signalr") from a javascript client I get this: "Error during negotiation request."

Instead of using mentioned Url if I use http://localhost:8080 from my PC I can Connect to SignalR.

Here is StartUp Class

public class Startup
{
    public void Configuration(IAppBuilder app)
    {
        app.Map("/signalr", map =>
        {
            app.UseCors(CorsOptions.AllowAll);
            var hubConfiguration = new HubConfiguration();

            map.RunSignalR(hubConfiguration);
        });
    }
}

Hub Class

public class SetupHub : Hub
{
    public void Send(string name, string message)
    {
        var msg = String.Format("{0}: {1} : {2}", name, message, DateTime.Now);
        Clients.All.addMessage(msg);            
    }
}

WebApiConfig Class

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {   
        // Web API configuration and services
        var cors = new EnableCorsAttribute("*", "*", "*");
        //  config.EnableCors();
        config.EnableCors(cors);

        // Web API routes
        config.MapHttpAttributeRoutes();

        config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );
    }
}

Global ASAX

public class WebApiApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        GlobalConfiguration.Configure(WebApiConfig.Register);
    }
}

JavaScript Client

var connection = $.hubConnection("http://192.168.9.6:3030/signalr");
var setupHubProxy = connection.createHubProxy('SetupHub');

setupHubProxy.on('addMessage', function (msg) {
    alert(msg);
});

connection.start()
        .done(function () {
            console.log('connected');
        })
    .fail(function (a) {
        console.log('not connected' + a);
    });

Any Help regarding this will be Highly Appreciated.

Answer 1

Error is in this line:

app.UseCors(CorsOptions.AllowAll);

It will be

map.UseCors(CorsOptions.AllowAll);

Answer 2

I have it in the web.config

<system.webServer>
    <httpProtocol>
      <customHeaders>
        <add name="Access-Control-Allow-Origin" value="*" />
      </customHeaders>
    </httpProtocol>

maybe this works for you too.