How to disable instance firewall on Ubuntu on Oracle Cloud

Note: This describes how to disable the firewall on an Ubuntu instance. You additionally need to configure the cloud network security list! See How to disable virtual cloud network firewall on Oracle Cloud for details!

The Oracle firewall is iptables based. We can disable the Ubuntu instance firewall using

sudo iptables -F
sudo netfilter-persistent save

Explanation:

• iptables -F: Flush (remove all) iptables rules
• netfilter-persistent save Save empty ruleset to disk so it will be reloaded on reboot.