Mastering Linux Security and Hardening - Second Edition

Hands-on lab for basic ufw usage

You'll need to complete this lab on a clean snapshot of your Ubuntu virtual machine. Let's get started:

1. Shut down your Ubuntu virtual machine and restore the snapshot to get rid of all of the iptables stuff that you just did. (Or, if you prefer, just start with a fresh virtual machine.)
2. When you've restarted the virtual machine, verify that the iptables rules are now gone:

sudo iptables -L

3. View the status of ufw. Open port 22/TCP and then enable ufw. Then, view the results:

sudo ufw statussudo ufw allow 22/tcpsudo ufw enablesudo ufw statussudo iptables -Lsudo ip6tables -L

4. This time, open port 53 for both TCP and UDP:

sudo ufw allow 53sudo iptables -Lsudo ip6tables -Lsudo ufw status

5. cd into the /etc/ufw ...