StatefulEngineOptions - AWS Network Firewall


Configuration settings for the handling of the stateful rule groups in a firewall policy.



Indicates how to manage the order of stateful rule evaluation for the policy. STRICT_ORDER is the default and recommended option. With STRICT_ORDER, provide your rules in the order that you want them to be evaluated. You can then choose one or more default actions for packets that don't match any rules. Choose STRICT_ORDER to have the stateful rules engine determine the evaluation order of your rules. The default action for this rule order is PASS, followed by DROP, REJECT, and ALERT actions. Stateful rules are provided to the rule engine as Suricata compatible strings, and Suricata evaluates them based on your settings. For more information, see Evaluation order for stateful rules in the AWS Network Firewall Developer Guide.

Type: String


Required: No


Configures how Network Firewall processes traffic when a network connection breaks midstream. Network connections can break due to disruptions in external networks or within the firewall itself.

  • DROP - Network Firewall fails closed and drops all subsequent traffic going to the firewall. This is the default behavior.

  • CONTINUE - Network Firewall continues to apply rules to the subsequent traffic without context from traffic before the break. This impacts the behavior of rules that depend on this context. For example, if you have a stateful rule to drop http traffic, Network Firewall won't match the traffic for this rule because the service won't have the context from session initialization defining the application layer protocol as HTTP. However, this behavior is rule dependent—a TCP-layer rule using a flow:stateless rule would still match, as would the aws:drop_strict default action.

  • REJECT - Network Firewall fails closed and drops all subsequent traffic going to the firewall. Network Firewall also sends a TCP reject packet back to your client so that the client can immediately establish a new session. Network Firewall will have context about the new session and will apply rules to the subsequent traffic.

Type: String


Required: No

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: