If your organization has an on-premise Active Directory with Azure AD with Active Directory Federation Services (ADFS) enabled, users can sign in to both cloud and on-premise resources using Azure AD Connect. For Barracuda Cloud Control services, you must use one of the following authentication methods:
- Password hash synchronization (PHS) – PHS enables users to log in to Barracuda Cloud Control using the same username and password that they use on-premises without having to deploy any additional infrastructure besides Azure AD Connect.
- Pass-through authentication (PTA) – This option is similar to password hash sync, but provides a simple password validation using on-premises software agents for organizations with strong security and compliance policies.
For additional information, refer to the Microsoft Azure article Azure AD Connect user sign-in options.