From my IT guy:

DDoS Deflate is a  bash shell script which purpose is blocking a denial of service attack.

the following installation guide is about cent os .

How to install

1. Login to Cent OS as root
2. run terminal
3. run the following commands
a. "wget http://www.inetbase.com/scripts/ddos/install.sh"
b. "chmod 0700 install.sh"
c. "./install.sh"


Configure

After installing the script the following directories and files
will be created

program directory =/usr/local/ddos
program =/usr/local/ddos/ddos.sh
ignore_ip_list=/usr/local/ddos/ignore.ip.list
cron (scheduller) =/etc/cron.d/ddos.cron
apf ( advanced policy firewall) =/etc/apf/apf
ipt (iptables) =/sbin/iptables

edit configuration file

run the following command on terminal
cd /usr/local/ddos
vi ddos.conf
( to edit the file with vi editor just type "i" , when finished  press escape then ":" "w" "q" and enter )

Configuration file settings

Freq= ( how often the script is executed in minutes )
Ddos - cron ( cron sceduller update )
No_of_connections ( number of connections received before an IP is blocked )
Apf_ban ( 1 means that it will use apf , 0 it will use iptables )
Ban_period ( time in seconds to block an IP )
Email_to ( address to send an email when an IP is blocked )
Kill ( when value is 0 no IP is banned )


In case you get blank IP edit the main script ddos.sh and replace

"netstat -ntu | awk ‘{print $5}’ | cut -d: -f1 | sort | uniq -c | sort -nr > $BAD_IP_LIST"

with this one

"netstat -ntu | grep ‘:’ | awk ‘{print $5}’ | sed ‘s/::ffff://’ | cut -f1 -d ‘:’ | sort | uniq -c | sort -nr > $BAD_IP_LIST"
( be sure to keep the command in a single line )


Uninstall  DDos Deflate

1. Login to Cent OS as root
2. run terminal
3. run the following commands
a. "wget http://www.inetbase.com/scripts/ddos/uninstall.sh"
b. "chmod 0700 uninstall.sh"
c. "./uninstall.sh"