After a firewall is created, you may need to enable it based on network security requirements. You can also disable an enabled firewall if need. Before enabling a firewall, ensure that subnets have been associated with the firewall and that inbound and outbound rules have been added to the firewall.
When a firewall is disabled, custom rules will become invalid. Disabling a firewall may interrupt network traffic. For information about the default firewall rules, see Default Firewall Rules.