netcore1.1_cookieAuthentication.cs

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    app.UseCookieAuthentication(new CookieAuthenticationOptions()
     {
         AuthenticationScheme = "MyCookieMiddlewareInstance",
         LoginPath = new PathString("/Account/Unauthorized/"),
         AccessDeniedPath = new PathString("/Account/Forbidden/"),
         AutomaticAuthenticate = true,
         AutomaticChallenge = true
     });
     app.UseMvc();
}