The LDAP Settings plugin handles issues related to LDAP settings.

At the moment the only diagnostic offered is the authentication test which will attempt to discover any issues with a given username and password.

The next screen enables you to enter the usernamd and password of the target user. The diagnostic will then use this information to attempt to authenticate the user as if a normal login request had been completed. The advantage in this is that it will work in a controlled environment and the login of the current user won't be changed.

From here we can see that the user was successfully authenticated with the username 'MOFFATS', an email address was discovered however there was a warning. A user already has the email address (called 'admin') and so if the user is relying on autocreation to be logged in then this will fail for the user and they will not be able to log in. Email address clashes are the most frequent problem as Joomla! enforces that all users must have a valid and unique email address.