====== Using UFW to Block Inbound Connections on Ubuntu ======

UFW, or Uncomplicated Firewall, is an interface to iptables that is geared towards simplifying the process of configuring a firewall.

UFW is installed by default on Ubuntu. If it has been uninstalled for some reason, you can install it with 
  sudo apt install ufw.

To set the defaults used by UFW, use these commands:
  sudo ufw default deny incoming
  
To configure your server to allow incoming SSH connections, you can use this command:
  sudo ufw allow ssh
or
  sudo ufw allow 22/tcp
  
==== Enabling UFW ====

To enable UFW, use the command:

  sudo ufw enable
  

Read more about UFW on the Ubuntu [[http://manpages.ubuntu.com/manpages/bionic/man8/ufw.8.html\man pages]]