A little help on freeradius with ldap

A little help on freeradius with ldap I configured freeradius 2.2.5 on debian 8.7 for authentication with LDAP following this usefull post and all works fine... http://mageconfig.blogspot.com/2014/11/configure-radius-with-ldap-for-networ... Freeradius pass the authentication's task to LDAP. How can I make that only the users present in mysql radius database are checked on LDAP ? I'm not much experienced whit linux ed freeradius. Sorry ! Thank you. Marco.