Install ufw:
sudo apt install ufw -y
Set default rules:
ufw default allow outgoing
ufw default deny incoming
Enable SSH (otherwise will result in a lockout ufw is enabled and the session ends):
ufw allow ssh
Enable example rules:
# human-readable syntax
ufw allow http
ufw allow https
...
# protocol/port syntax
ufw allow 51820/udp
ufw allow 8081/tcp
...
Enable ufw:
ufw enable
Disable ufw:
ufw disable
View firewall status:
ufw status
