1. Enter the Temp Directory

cd /tmp/

2. Download the CSF Package

wget https://download.configserver.com/csf.tgz

3. Extract the package

tar -xzf csf.tgz

4. Enter the extracted CSF directory

cd csf

4. Run the Installer

sh install.sh

5. Test the CSF Installation

perl /usr/local/csf/bin/csftest.pl

Expected output should be as below

Testing ip_tables/iptable_filter…OK
Testing ipt_LOG…OK
Testing ipt_multiport/xt_multiport…OK
Testing ipt_REJECT…OK
Testing ipt_state/xt_state…OK
Testing ipt_limit/xt_limit…OK
Testing ipt_recent…OK
Testing xt_connlimit…OK
Testing ipt_owner/xt_owner…OK
Testing iptable_nat/ipt_REDIRECT…OK
Testing iptable_nat/ipt_DNAT…OK

RESULT: csf should function on this server

This means that all the CSF modules are installed and functioning properly.