Based on your smb.conf, you must have the following entries in /etc/ldap.conf nss_base_passwd ou=Users,dc=DOMAIN,dc=IT?one nss_base_passwd ou=Computers,dc=DOMAIN,dc=IT?one nss_base_shadow ou=Users,dc=DOMAIN,dc=IT?one nss_base_group ou=Groups,dc=DOMAIN,dc=IT?one