Server security should be on the top of your priority list when you own a dedicated server. So, to have a better security a third party application such as a secured firewall must be installed on your server. But, before that it is necessary to consider how much can you afford to get a secured firewall for your server.
In such a case, you should opt for a Free Open Source Firewall called as CSF (ConfigServer Security and Firewall). CSF is a firewall which is frequently updated and provides lots of options in order to strengthen your server security from well known attacks.
In order to start, restart and flush the CSF rules you need to install it on your server. If you are not sure about the CSF installation, check out the following tutorial:
How to Install CSF (ConfigServer Security and Firewall)?
Once you have successfully installed the CSF Firewall, you can proceed with the Enable, Restart and Flush process.
Enabling the CSF Enter the following command:
Restarting the CSF Enter the following command:
Flushing the CSF Rules Enter the following command: