ufw status 
ufw status numbered

ufw allow PORT

ufw allow PORT/tcp

ufw allow PORT/tcp
ufw allow proto tcp to any port PORT

ufw allow PORT1:PORT2/tcp

ufw allow in on ETH0 to any port PORT

ufw delete NUMBER // 通过编号删除
sudo ufw delete 1
ufw delte allow PORT // 通过规则删除
sudo ufw delete allow 80/tcp

ufw allow from IP/24 to any port PORT

ufw deny from IP/24 to any port PORT

ufw reset

ufw app list
ufw app info
ufw allow 'VNC'

sudo ufw status verbose
# Status: active
# Logging: on (low)
# Default: deny (incoming), allow (outgoing), deny (routed)
# New profiles: skip

sudo ufw logging on

sudo tail -n 10 /var/log/ufw.log

sudo tail -f /var/log/ufw.log

sudo less /var/log/ufw.log