Information
The Uncomplicated Firewall (ufw) is a frontend for iptables and is particularly well-suited for host-based firewalls. ufw provides a framework for managing netfilter, as well as a command-line interface for manipulating the firewall
A firewall utility is required to configure the Linux kernel's netfilter framework via the iptables or nftables back-end.
The Linux kernel's netfilter framework host-based firewall can protect against threats originating from within a corporate network to include malicious mobile code and poorly configured software on a host.
Note: Only one firewall utility should be installed and configured. UFW is dependent on the iptables package
Solution
Run the following command to install Uncomplicated Firewall (UFW):
apt install ufw