Mastering Active Directory - Second Edition

Pass-through authentication

To create federation trusts between Azure AD and on-premises AD, quite a bit of work is involved. We need additional servers, SSL certificates, licenses, HA solution, firewall changes, and advanced configurations. But Azure AD pass-through authentication allows organizations to do on-premises only user authentication with minimum changes being made to the environment. It uses an agent (https://aka.ms/getauthagent) that can be installed on any Windows server. By using pass-through authentication, users can do the following:

• Authenticate into Azure AD and on-premises AD using the same password.
• Authentication for on-premises users will always be processed through on-premises AD.
• Pass-through authentication feature ...