Mod_evasive is an Apache module designed to protect Apache against DOS or brute force attacks.
What is mod_evasive?
mod_evasive is an evasive maneuvers module for Apache to provide evasive action in the event of an HTTP DoS or DDoS attack or brute force attack. It is also designed to be a detection and network management tool, and can be easily configured to talk to ipchains, firewalls, routers, and etcetera. mod_evasive presently reports abuses via email and syslog facilities.
Detection is performed by creating an internal dynamic hash table of IP Addresses and URIs, and denying any single IP address from any of the following:
- Requesting the same page more than a few times per second
- Making more than 50 concurrent requests on the same child per second
- Making any requests while temporarily blacklisted (on a blocking list)
Installing mod_evasive is disappointingly easy in Ubuntu 9.04 :
sudo apt-get install libapache2-mod-evasive
That is all there is to it.
How to test that it works ? Simply open any browser, got to your server’s home page, and click the reload button as fast as you can.