Quck Start

https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-with-ufw-on-ubuntu

Should be yes:

grep IPV6 /etc/default/ufw

sudo ufw default deny incoming

sudo ufw default allow outgoing

sudo ufw allow OpenSSH

sudo ufw show added

sudo ufw enable

Examples

sudo ufw allow OpenSSH

sudo ufw allow ssh

sudo ufw allow 22

HTTP on port 80, which is what unencrypted web servers use, using sudo ufw allow http or sudo ufw allow 80

HTTPS on port 443, which is what encrypted web servers use, using sudo ufw allow https or sudo ufw allow 443

Apache with both HTTP and HTTPS, using sudo ufw allow ‘Apache Full’

Nginx with both HTTP and HTTPS, using sudo ufw allow ‘Nginx Full’

Port Ranges

sudo ufw allow 6000:6007/tcp

sudo ufw allow 6000:6007/udp

sudo ufw allow from 203.0.113.4 to any port 22

Interfaces

sudo ufw allow in on eth0 to any port 80

Denying

sudo ufw deny http

sudo ufw deny from 203.0.113.4

Delete Rule

sudo ufw status numbered

sudo ufw delete 2