Prevent DoS attacks with mod evasive

To protect your server from DoS attacks on te webserver you might want to install mod_evasive.

Attention: Some CalDAV clients really bomb the server the fetch data. If you experience problems after installing mod_evasive disable it or try less strict settings

Install the Debian package:

$ apt-get install libapache2-mod-evasive

Add the module to Apache:

$ a2enmod evasive

Edit /etc/apache2/mods-enabled/evasive.conf and enter the following:

<IfModule mod_evasive20.c>
    DOSHashTableSize    3097
    DOSPageCount        100
    DOSSiteCount        100
    DOSPageInterval     15
    DOSSiteInterval     15
    DOSBlockingPeriod   60
</IfModule>

We tested this configuration it works well with Group-Office.