About Mvc routes

I want to set a rule only for defaultController

 routes.MapRoute(
     name: "testDefault",
     url: "Default/{action}/{id}.html",
     defaults: new { controller = "Default", action = "Index", id = UrlParameter.Optional }
 );
 routes.MapRoute(
     name: "Default",
     url: "{controller}/{action}/{id}",
     defaults: new { 
          controller = "Test", 
          action = "Show", 
          id = UrlParameter.Optional 
     }
);

However, http://ift.tt/1ds6NNi also can be open ,This is not what I want。Someone can help me?