Allow access to the site that some users

Hi,

I made an intranet site with authentication via LDAP, and I liked how it was to allow only certain people to log on the site?

In access rights can allow people, but a person not in this list may still be logged if it is not prohibited.

I have a twenty person and to allow more than 500 to prohibit, it is too much work, is it possible to prohibit everyone except my twenties?

I did some testing and made it a rule to prohibit access, and as a user I put "%" if I understand it will be include all peoples, I then test me login with my LDAP account and there message saying that the name is reserved, in short I'm glad it works, I try in the wake of log me again and here I am logged in perfectly and I access to content and so on. And my user is not in the list of users, I had deleted before.

Thank you for your help,

Romain (sorry my english, I'm french)