Only allow certain (dynamic) IP's to visit website director

OK

I have 4 dynamic ips, in order to get those IP's I need run a gethostbyname('domain_name.com'); on 4 domain names I have that alwasy resolve开发者_开发问答 to the only 4 IP's that are allowed to access this directory.

This is very easy for me to do on a PHP script on a page, but I am confused as how I can do it to a directory?

Thanks!!

---

AFAIK you can use hostnames in htaccess, like this:

.htaccess:

Deny From All
Allow From host1.com
Allow From host2.com