... and against Microsoft Active Directory?

To authenticate against a Microsoft Active Directory the following bare minimum example configuration for 'test.org' with an active directory server at 123.123.123.123 of /etc/ldap.conf Directory is what you would require:

   host 123.123.123.123
   base cn=Users,dc=test,dc=org
   rootbinddn cn=Administrator,cn=Users,dc=test,dc=org
   pam_filter objectclass=user
   pam_login_attribute cn

With the password for the Administrator user in the file /etc/ldap.secret and chowned to 0600.

Thanks to: Alexander Cohen <A.Cohen@latrobe.edu.au>.