If pass-through authentication is enabled but login attempts are unsuccessful, what might be the issue?

When pass-through authentication is enabled, the process allows users to log in to a system without providing credentials directly to that system. Instead, their credentials are passed to the on-premises domain controller to authenticate the user. If login attempts are unsuccessful, one potential issue is that an agent responsible for this communication with the on-premises domain controllers is not installed. Without this agent, the system cannot verify user credentials against the domain, leading to failed login attempts.

The installation of this agent is crucial because it facilitates the secure transfer of authentication requests and ensures that the system can effectively communicate with the domain controllers. If the agent is missing or improperly configured, it will prevent valid login attempts from succeeding.

Other issues such as lack of an internet connection or user account locking could also affect the ability to authenticate, but they do not relate specifically to the pass-through authentication infrastructure. Similarly, incorrect group membership impacts authorization rather than authentication. Therefore, the absence of the agent is the most direct cause for unsuccessful login attempts in this scenario.