We dive right into the CIS Ubuntu Linux 16.04 LTS Benchmark. We talk about what this is, level 1 and level 2 recommendations and several examples. This includes SSH, partitions, iptables, ufw and AIDE. We will be incorporating some of these recommendations into our own Ubuntu systems. We also go over future plans and projects.

Firewall Script & Commands

  1. iptables firewall script PDF: CIS iptables firewall script
  2. To list the iptables firewall rules: iptables -L
  3. To list the iptables firewall rules & get more information: iptables -L -n -v
  4. To check the status of the ufw firewall & list the rules: ufw status
  5. To enable the ufw firewall: ufw enable


  1. CIS – Center for Internet Security


The ssh configuration file has options. To make it more secure you need to apply the recommended options from the CIS benchmark. We also recommend you move ssh to a port above 1024 and implement ssh keys.