I have a large enterprise application containing both WebForms and MVC pages. It has existing authentication and authorisation settings that I don\'t want to change.
In .NET 4.5 you can now set
Response.SuppressFormsAuthenticationRedirect = true
Check this page: https://msdn.microsoft.com/en-us/library/system.web.httpresponse.suppressformsauthenticationredirect.aspx