====== General ======
===== Installing =====
ufw should be installed by default on newer Ubuntu servers. (Although it is most likely disabled)
===== Enabling =====
sudo ufw default allow # Careful, uwf by default DENIES all incoming traffic. So I first set it to "allow" here to avoid being locked out of the server
sudo ufw enable
===== Checking status =====
sudo ufw status verbose
====== Adding Rules ======
===== Block an IP =====
sudo ufw deny from 10.101.21.228
===== Block a Port =====
sudo ufw deny 53
====== Removing Rules ======
sudo ufw delete deny from 10.101.21.228
====== External Links ======
* https://help.ubuntu.com/community/UFW
* http://1000umbrellas.com/2010/04/29/how-to-set-up-the-firewall-using-ufw-on-ubuntu-lucid-lynx-server
* https://help.ubuntu.com/8.04/serverguide/C/firewall.html