streamExceptionPolicy

Indicates how Network Firewall should handle traffic when a network connection breaks midstream.

• DROP - Fail closed and drop all subsequent traffic going to the firewall.

• CONTINUE - Continue to apply rules to subsequent traffic without context from traffic before the break. This impacts the behavior of rules that depend on context. For example, with a stateful rule that drops HTTP traffic, Network Firewall won't match subsequent traffic because the it won't have the context from session initialization, which defines the application layer protocol as HTTP. However, a TCP-layer rule using a flow:stateless rule would still match, and so would the aws:drop_strict default action.

• REJECT - Fail closed and drop all subsequent traffic going to the firewall. With this option, Network Firewall also sends a TCP reject packet back to the client so the client can immediately establish a new session. With the new session, Network Firewall will have context and will apply rules appropriately.For applications that are reliant on long-lived TCP connections that trigger Gateway Load Balancer idle timeouts, this is the recommended setting.

• FMS_IGNORE - Firewall Manager doesn't monitor or modify the Network Firewall stream exception policy settings.

For more information, see Stream exception policy in your firewall policy in the Network Firewall Developer Guide.

Default: FMS_IGNORE