Owncloud - LDAP. Acces from IP

Good morning, I'm running latest version stable.
I have Owncloud connected with LDAP. Its working fine, but I want to restrict some users from external net.
Only 3-4 users should login from external, rest only from internal IP (same range than Owncloud). It is possible?

My actual chain LDAP -> (&(objectclass=mailUser)(enabledService=owncloud))

All members have that "object -> owncloud" but only some should login from external.

Server configuration
Operating system: Ubuntu
Web server: Nginx
Database: MariaDB
PHP version: 5.X
ownCloud version (see ownCloud admin page): latest stable

BTW, are there any log with all info from users? Delete/Add/Share...

Thanks you.