My requirements are:-

1. To build an ASP.NET MVC web application to use windows based authentication, since all the users which will be accessing the application are our internal employees, and they have username and password on our company Active Directory.

So as I understand the windows authentication inside ASP.NET MVC be valid:-

1. If an employee accesses the web application inside our company intranet then he will be able to login to the MVC application automatically (without the need to enter a username and password).
2. If the user login to the application using VPN from outside the company intranet, then he still can access the application automatically without the need to enter username and password.
3. But when happen if the user accesses the asp.net MVC web application using an operating system other than windows such as Linux. Will windows base authentication worked from inside or outside the company intranet?
4. What will happen if a user accesses the web application from outside the company network using his personal PC using windows operating system?