# Considerations and disclaimers for using Amazon managed rule groups in Network Firewall
Considerations and disclaimers

Before you add Amazon managed rule groups to a firewall policy, consider the following.

**Disclaimer**  
Managed rule groups are designed to protect you from common web threats. When used in accordance with the documentation, Amazon managed rule groups add another layer of security for your applications. However, Amazon managed rule groups aren't intended as a replacement for your security responsibilities, which are determined by the Amazon resources that you select. Refer to the [Shared Responsibility Model](http://www.amazonaws.cn/compliance/shared-responsibility-model/) to ensure that your resources in Amazon are properly protected. 

**DNS traffic limitations**  
Network Firewall filters network traffic that is routed through firewall endpoints. However, DNS queries made to Amazon Route 53 Resolver are not inspected because they are routed to a static address in the VPC. Any DNS inspection rules in Amazon managed rule groups, including active threat defense managed rule groups, cannot inspect traffic to Amazon Route 53 Resolver. For more information about Network Firewall limitations, see [Limitations and caveats for stateful rules in Amazon Network FirewallLimitations and caveats](suricata-limitations-caveats.md).

**Automatic updates**  
Amazon automatically updates managed rule groups to protect against new vulnerabilities and threats. These updates can occur daily to weekly, depending on threat severity. Sometimes, Amazon is notified of new vulnerabilities before public disclosure due to its participation in a number of private disclosure communities. In those cases, Network Firewall may update rule groups and deploy them to your environment before a new threat is widely known.

**Copying Amazon managed rules**  
You can copy managed threat signature rules into your own rule group and customize them for your specific needs, but Network Firewall does not supporting copying active threat defense rules.