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
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’
sudo ufw allow 6000:6007/tcp
sudo ufw allow 6000:6007/udp
sudo ufw allow from 203.0.113.4 to any port 22
sudo ufw allow in on eth0 to any port 80
sudo ufw deny http
sudo ufw deny from 203.0.113.4
sudo ufw status numbered
sudo ufw delete 2