Installing and Configuring CSF Firewall

 Steps to Install CSF Firewall on Centos 7

Step 1: Downloading CSF Firewall Dependencies

yum install wget vim perl-libwww-perl.noarch perl-Time-HiRes

Step 2: Install CSF

Go to /usr/src

#cd /usr/src

Download CSF Firewall

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

#tar -xvf csf.tar

#cd csf

#sh install .sh

Step 3: Checking CSF Working on server or not

#cd /usr/local/csf/bin/

#perl csftest.pl

If you see the test results as shown below, 

then CSF is running without problems on your server:

RESULT: csf should function on this server

Step 4: Configuring CSF Firewall on Centos 7

1. Stop Firewalld

#systemctl stop firewalld

2. Disable/Remove firewalld from the startup:

#systemctl disable firewalld

3. Then go to the CSF Configuration directory

"/etc/csf/" and edit the file "csf.conf" 

with the vim editor:

#cd /etc/csf/

#vim csf.conf

4. Change line 11 "TESTING " to "0" for applying the 

firewall configuration.

TESTING = "0"

5. By default CSF allows incoming and outgoing 

traffic for the SSH standard port 22, 

if you use a different SSH port then 

please add your port to the configuration 

in line 139 "TCP_IN".

6. Now start CSF and LFD with systemctl command:

#systemctl start csf

#systemctl start lfd

7. Enable CSF and LFD

#systemctl enable csf

#systemctl enable lfd

8. You can see the list default rules of CSF 

with command:

#csf -l

Step 5 Basic CSF Commands

Start the Firewall

#csf -s

Flush/stop firewall rules

#csf -f

Reload the Firewall Rules

#csf -f

Allow an IP and add it to csf.allow

#csf -a ipaddress

Remove an Ip

#csf -ar ipaddress

Advanced Configuration File

#cd /etc/csf

#vim csf.conf