Use mod_evasive for block DOS attack

written by Mr-San.com on November 25, 2006 in Howto with no comments

In some cases, your web server have attacked by someone how to resolve this problem?

Use mod_evasive to resolve this problem

When mod_evasive detects attack, it will create hash table and deny that ip 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)

You can get this module via : http://www.zdziarski.com/projects/mod_evasive/mod_evasive_1.10.1.tar.gz

How to install?

• extract mod_evasive_1.10.1.tar.gz
• change directory to /usr/local/apache2/bin ( or somewhere for apxs)
• compile mod_evasive with :
  for apache v.2.x
  apxs -i -a -c mod_dosevasive20.c

  for apache v.1.x
  apxs -iac mod_evasive.c

• add this to httpd.conf
  for apache v.2.x
  LoadModule evasive20_module /usr/lib/apache2/modules/mod_evasive20.so

  for apache v.1.x
  LoadModule evasive_module /usr/lib/apache2/modules/mod_evasive.so

• edit httpd.conf for config mod_evasive
  for apache v2.x
  <IfModule mod_evasive20.c>
  DOSHashTableSize 3097
  DOSPageCount 2
  DOSSiteCount 50
  DOSPageInterval 1
  DOSSiteInterval 1
  DOSBlockingPeriod 10
  </IfModule>

  for apache v1.x
  <IfModule mod_evasive.c>
  DOSHashTableSize 3097
  DOSPageCount 2
  DOSSiteCount 50
  DOSPageInterval 1
  DOSSiteInterval 1
  DOSBlockingPeriod 10
  </IfModule>

• then restart apache

You can found some information about mod_evasive at : http://www.zdziarski.com/projects/mod_evasive/

tags: apache dos-attack mod-evasive

---

Related Articles