Working with web ACLs - Amazon WAF, Amazon Firewall Manager, and Amazon Shield Advanced
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Working with web ACLs

This section provides procedures for creating, managing, and using web ACLs through the Amazon console.

For any web ACL that you're using, you can access summaries of the web traffic metrics on the web ACL's page in the Amazon WAF console, under the Traffic overview tab. The console dashboards provide near real-time summaries of the Amazon CloudWatch metrics that Amazon WAF collects when it evaluates your application web traffic. For more information about the dashboards, see Web ACL traffic overview dashboards. For additional information about monitoring your web ACL's traffic, see Monitoring and tuning.

Production traffic risk

Before you deploy changes in your web ACL for production traffic, test and tune them in a staging or testing environment until you are comfortable with the potential impact to your traffic. Then test and tune your updated rules in count mode with your production traffic before enabling them. For guidance, see Testing and tuning your Amazon WAF protections.


Using more than 1,500 WCUs in a web ACL incurs costs beyond the basic web ACL price. For more information, see Amazon WAF web ACL capacity units (WCUs) and Amazon WAF Pricing.

Temporary inconsistencies during updates

When you create or change a web ACL or other Amazon WAF resources, the changes take a small amount of time to propagate to all areas where the resources are stored. The propagation time can be from a few seconds to a number of minutes.

The following are examples of the temporary inconsistencies that you might notice during change propagation:

  • After you create a web ACL, if you try to associate it with a resource, you might get an exception indicating that the web ACL is unavailable.

  • After you add a rule group to a web ACL, the new rule group rules might be in effect in one area where the web ACL is used and not in another.

  • After you change a rule action setting, you might see the old action in some places and the new action in others.

  • After you add an IP address to an IP set that is in use in a blocking rule, the new address might be blocked in one area while still allowed in another.