Mixed authorization in MVC 4, Windows and Forms

Question

Active Directory

I am developing an MVC application for intranet and internet users of our company.
It is necessary to implement mixed authorization. If an AD user has entered the site, then you need to authorize using windows authorization, and if a user who is not in Active Directory has entered the site, then you need to direct him to the authorization form.
Please tell me the best way to implement this.
Thank you!