UFW cheatsheet
https://pupli.net/2019/06/ufw-cheatsheet/
Block an IP Address using UFW
https://pupli.net/2021/04/block-an-ip-address-using-ufw/
Allow Incoming Connection from Specific IP Address or Subnet in UFW
https://pupli.net/2021/04/allow-incoming-connection-from-specific-ip-address-or-subnet-in-ufw/
Disable IPv6 on UFW on Linux
https://pupli.net/2022/10/disable-ipv6-on-ufw-on-linux/