If your search result is larger then the directory limit, it will just show you the maximum number of return entries possible by the directory (.e.g 2000 in some ActiveDirectories)
(PHP 4, PHP 5)
ldap_count_entries — Count the number of entries in a search
Returns the number of entries stored in the result of previous search operations.
An LDAP link identifier, returned by ldap_connect().
The internal LDAP result.
Returns number of entries in the result or FALSE on error.