Installing mod_evasive

Installing mod_evasive (formally known as mod_dosevasive)
Login too your server and execute

cd /usr/local/src
wget http://www.zdziarski.com/projects/mod_evasive/mod_evasive_1.10.1.tar.gz
tar -zxvf mod_evasive_1.10.1.tar.gz
cd mod_evasive

For apache 2.0.x
/usr/sbin/apxs -cia mod_evasive20.c

Then add add this too httpd.conf

DOSHashTableSize 3097
DOSPageCount 6
DOSSiteCount 100
DOSPageInterval 2
DOSSiteInterval 2
DOSBlockingPeriod 600

For apache 1.3.x

usr/local/apache/bin/apxs -cia mod_evasive.c

Then add this too httpd.conf

DOSHashTableSize 3097
DOSPageCount 6
DOSSiteCount 100
DOSPageInterval 2
DOSSiteInterval 2
DOSBlockingPeriod 600

Now just restart apache and the installation is complete.
/etc/init.d/httpd restart