Basically, the instructions call for setting up a "black list," or "restricted from access" set of rules. While this will work, keep in mind that the issue with black lists is they tend to become outdated as new threats emerge. While this is one way to restrict access, another more secure way is to use a Web access management (WAM) product in front of the Apache server. This allows access to be managed based on a "white list," or only those users authorized to access the Web server. A WAM can provide single sign-on, while also having less of an impact on your security infrastructure, since access is granted as needed, instead of denied as needed.
A WAM can also provide access to multiple Apache servers from a single domain, reducing administrative costs. Since the Apache Web server is most likely Internet facing, front-ending it with a WAM will reduce your risk of attack, since the WAM provides more powerful authentication and control tools.
This was first published in June 2010