使用identityServer时如何选择退出身份验证？

I'm trying WIF and using identityServer. My question is how can one opt of requiring auth on controller or controller methods ( ASP.NET MVC 4 ). I have previously used [AllowAnonymous] attribute. Anyone have any samples of how to do this? This code still redirects to the identityServer for login.I'm trying WIF and using identityServer. My que