I want to have several domains A, B, C where a user can enter his username and password to login to a common main domain D.
So the user goes to A, B or C, enters his username and password, clicks the "login" button, and is then on the main domain D in a logged in/authenticated state. Then the user does the things he wants to do, and then clicks the logout-button and is then returned to the original domain that he came from, be it A, B or C.
What is the best way to do this?
I currently use forms authentication in ASP.NET 4.0 (C#).
Thanks,