for myself hosted with OVH which has ddos protection as standard but also on the server side use mod_antiloris.
1. Download the installer and install from Sourceforge.net:
$ cd /usr/local/src
$ wget http://sourceforge.net/projects/mod-antiloris/files/mod_antiloris-0.4.tar.bz2/download
$ tar -xvjf mod_antiloris-0.4.tar.bz2
$ cd mod_antiloris-*
$ apxs -a -i -c mod_antiloris.c
2. Restart Apache:
$ service httpd restart