I installed mod_security quite simply by using yum. Once it was installed I added the base rules from OWASP (http://sourceforge.net/projects/mod-security/files/modsecurity-crs/0-CURRENT/) to the new mod_security.conf file that the yum install added to the conf.d directory of apache. However I quickly found that this ruleset is a bit too draconian. You will want to take some time [...]
Please check out our article on building a hardened lamp server. It contains much more information on IPTables, PSAD and OSSEC Installation: IPTables is installed automatically with almost all installations of CentOS, if it is not installed it can be simply installed with the command yum install iptables Building the ruleset: See the CentOS Wiki [...]
http://www.untangle.com/ The Untangle Lite package offers a collection of free, open-source software applications to run on the Untangle Server. It provides an entry-level multi-functional firewall, with: Web Filter Lite Virus Blocker Spam Blocker Attack Blocker Phish Blocker Spyware Blocker Protocol Control Captive Portal Firewall Intrusion Prevention OpenVPN Reports