Usage of apf-firewall on Ubuntu

Example 1: Load firewall Rules

This will load all the firewall configuration options.

apf -o

We have got the details of the firewall configuration.

Example 2: List of Firewall Rules

This command list all the firewall rules present in our Ubuntu Operating System.

apf -l

The below screenshot describes the list of available or present firewalls on the system.

Example 3: Status 

Show the status of output’s the firewall log.

apf -t

APF, or Advanced Policy Firewall, is a firewall that is occasionally observed on Liquid Web servers. It is essentially an interface to iptables, which is Linux’s standard interface for controlling network ports. Interacting with iptables may be complicated and error-prone, but APF substantially simplifies it. APF, on the other hand, is still only accessible via ssh. Changes to APF cannot be made using WHM or cPanel. All APF configuration files are stored on your server in the /etc/apf subdirectory. They allow hosts.rules file in this folder contains all of the IP addresses that are whitelisted for the server, while the deny hosts.rules file contains all of the IP addresses that are prohibited by the firewall. Each IP address that is prohibited should contain a justification for the block in the denied hosts.rules file (most of them will be blocked by bfd, which blocks IPs attempting to brute force the server).