Mastering Linux Security and Hardening

Hands-on lab for basic ufw usage

You'll do this lab on a clean snapshot of your Ubuntu virtual machine:

1. Shut down your Ubuntu virtual machine and restore the snapshot. (You want to do this to get rid of all of the iptables stuff that you just did.)
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, enable it, and view the results:

         sudo ufw status         sudo ufw enable         sudo ufw status         sudo iptables -L         sudo ip6tables -L

4. Open port 22/tcp to allow Secure Shell access:

        sudo ufw allow 22/tcp        sudo iptables -L        sudo ip6tables -L

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

        sudo ufw allow 53        sudo iptables -L        sudo ip6tables -L

6. End of lab.