How to protect Apache against DOS,DDOS or brute force attacks
Posted by Admin on May 12th, 2009
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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)
This method has worked well in both single-server script attacks as well as distributed attacks, but just like other evasive tools, is only as useful to the point of bandwidth and processor consumption (e.g. the amount of bandwidth and processor required to receive/process/respond to invalid requests), which is why it’s a good idea to integrate this with your firewalls and routers for maximum protection.
This module instantiates for each listener individually, and therefore has a built-in cleanup mechanism and scaling capabilities. Because of this per-child design, legitimate requests are never compromised (even from proxies and NAT addresses) but only scripted attacks. Even a user repeatedly clicking on ‘reload’ should not be affected unless they do it maliciously. mod_evasive is fully tweakable through the Apache configuration file, easy to incorporate into your web server, and easy to use.
Install mod_evasive in Debian
#apt-get install libapache2-mod-evasive
This will complete the installation
Test mod_evasive Module
open any browser,open your apache server home page, and click the reload button as fast as you can.
May 15th, 2009 at 2:42 am
Just install or are there something configuration ?
May 18th, 2009 at 10:51 am
I don’t think it will block DDos attacks since the requests will come from a lot of different IP addresses.
May 26th, 2009 at 5:32 am
mod_evasive has a very limited scope. If you really suffer from an application level DDoS you will feel very weak if this is your only tool. Better look into mod_qos. It has a lot more to offer.
July 10th, 2009 at 9:44 pm
thanks for your solution
I have found mod_security, Is mod_evasive better than mod_security ?? what advantages has?
thanks
October 3rd, 2009 at 1:47 pm
I’ve installed mod_evasive, even added some config options I found online to httpd.conf. slowloris still 0wns the server. fail.
November 11th, 2009 at 7:14 pm
Real protection is only Load Balancer / Proxy not a mod_ for Apache.