I guess the first step is to make sure you can talk to your "zentyal (??) server 4.1 running samba4" via LDAP. And if you need credentials to do so, or if it allows anonymous bind. There are several ways to browse an ldap directory out there… I use java-based LDAPBrowser, for example. Once you know how to connect, credentials required or not, what the schema is (and where users/groups are)… then you can move forward