AWS::NetworkFirewall::FirewallPolicy StatefulEngineOptions - AWS CloudFormation
SyntaxProperties

AWS::NetworkFirewall::FirewallPolicy StatefulEngineOptions

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

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

JSON

{
  "FlowTimeouts" : FlowTimeouts,
  "RuleOrder" : String,
  "StreamExceptionPolicy" : String
}

Properties

FlowTimeouts

Configures the amount of time that can pass without any traffic sent through the firewall before the firewall determines that the connection is idle.

Required: No

Type: FlowTimeouts

Update requires: No interruption

RuleOrder

Indicates how to manage the order of stateful rule evaluation for the policy. DEFAULT_ACTION_ORDER is the default behavior. Stateful rules are provided to the rule engine as Suricata compatible strings, and Suricata evaluates them based on certain settings. For more information, see Evaluation order for stateful rules in the AWS Network Firewall Developer Guide.

Required: No

Type: String

Allowed values: DEFAULT_ACTION_ORDER | STRICT_ORDER

Update requires: No interruption

StreamExceptionPolicy

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.

Required: No

Type: String

Allowed values: DROP | CONTINUE | REJECT

Update requires: No interruption