Zentyal It is an excellent option to implement a server easily and quickly in the SMEs. With every release Zentyal adds improvements, corrections and becomes the ideal solution for small-format corporate networks.
A common mistake comes to light when the 500 users, since by default LDAP set that amount by default. The solution for that lies in adding the line:
at the end of the file /etc/ldap/slapd.d/cn=config/olcDatabase=[1-lex.europa.euhdb.ldif
We reboot ldap and ready..