iptables configuration on OCI ubuntu instance:
➜ ~ sudo iptables -I INPUT 6 -m state --state NEW -p tcp --dport 80 -j ACCEPT
➜ ~ sudo iptables -I INPUT 6 -m state --state NEW -p tcp --dport 443 -j ACCEPT
➜ ~ sudo netfilter-persistent save
@mashiro 直接扬了
sudo apt remove ufw firewalld iptables -y 
