• https://www.digitalocean.com/community/tutorials/ufw-essentials-common-firewall-rules-and-commands
• https://linuxize.com/post/how-to-setup-a-firewall-with-ufw-on-ubuntu-20-04/

sudo ufw app list

• Change x to an app listed in above command

sudo ufw app info x

• TODO: What does limit actually do?

sudo ufw limit ssh

• 22 is the port number and tcp is the protocol
• udp can be a protocol

sudo ufw allow 22/tcp