I haven't used it in 4 years but back when I did I kept notes and collected web post and articles on how to install and use it.

The info is out of date but what you need to know is the basics and that might not have changed very much (unless they did a total rewrite). At least it might help to understand the current documentation.

If you want a copy of my notes I could zip them and upload them to a free file server then post the download link here for you. The zipped file will contain other info on Apache "protection" software as well .

I liked mod_security a lot. It was worth the effort to learn to use. But you will have to know regex to get the best use from it. Using regex filters can have "unexpected consequences" so you will need to monitor the logs to make sure you are not blocking something you did not want to block. I used it to block spam post and it blocked about 200,000 per day without any problems.

This is not for CentOS however it's probably one of the quickest and easiest tutorials on mod_sec that I've come across. You shouldn't have too many problems adapting it to CentOS.

http://tmacuk.co.uk/perso ...