External Authentication and Redirect

For example:
If someone try to acess my website is redirected to the Authentication website.
The only way to see my website is login in the Authentication website and then redirected to my website.
Is there a simple way to to this?

Use “Page is loaded” workflows to add Actions to Navigate to Authentication page “only when Current User is logged out”. This way if anyone is not authenticated and tries to access your site it will automatically send them to the login/authentication page.