-----
You don't give the actual command that is failing
ldapsearch -x -h localhost \
-D "cn=sole,dc=progetto-sole,dc=it" \
-b "dc=progetto-sole,dc=it" \
-W '(cn=sole)'
or if you wanted write access...
ldapsearch -x -h localhost \
-D "cn=Manager,dc=progetto-sole,dc=it" \
-b "dc=progetto-sole,dc=it" \
-W '(cn=sole)'
Probably best to have a contain for 'users' - something like
ou=People,dc=progetto-sole,dc=it
and put users like sole in that container...
uid=sole,ou=People,dc=progetto-sole,dc=it
Craig