This is AWS WAF Classic documentation. For more information, see AWS WAF Classic in the developer guide.

For the latest version of AWS WAF, use the AWS WAFV2 API and see the AWS WAF Developer Guide. With the latest version, AWS WAF has a single set of endpoints for regional and global use.

Inserts or deletes ActivatedRule objects in a WebACL. Each Rule identifies web requests that you want to allow, block, or count. When you update a WebACL, you specify the following values:

• A default action for the WebACL, either ALLOW or BLOCK. AWS WAF performs the default action if a request doesn't match the criteria in any of the Rules in a WebACL.
• The Rules that you want to add or delete. If you want to replace one Rule with another, you delete the existing Rule and add the new one.
• For each Rule, whether you want AWS WAF to allow requests, block requests, or count requests that match the conditions in the Rule.
• The order in which you want AWS WAF to evaluate the Rules in a WebACL. If you add more than one Rule to a WebACL, AWS WAF evaluates each request against the Rules in order based on the value of Priority. (The Rule that has the lowest value for Priority is evaluated first.) When a web request matches all the predicates (such as ByteMatchSets and IPSets) in a Rule, AWS WAF immediately takes the corresponding action, allow or block, and doesn't evaluate the request against the remaining Rules in the WebACL, if any.

To create and configure a WebACL, perform the following steps:

1. Create and update the predicates that you want to include in Rules. For more information, see CreateByteMatchSet, UpdateByteMatchSet, CreateIPSet, UpdateIPSet, CreateSqlInjectionMatchSet, and UpdateSqlInjectionMatchSet.
2. Create and update the Rules that you want to include in the WebACL. For more information, see CreateRule and UpdateRule.
3. Create a WebACL. See CreateWebACL.
4. Use GetChangeToken to get the change token that you provide in the ChangeToken parameter of an UpdateWebACL request.

5. Submit an UpdateWebACL request to specify the Rules that you want to include in the WebACL, to specify the default action, and to associate the WebACL with a CloudFront distribution.

   The ActivatedRule can be a rule group. If you specify a rule group as your ActivatedRule , you can exclude specific rules from that rule group.

   If you already have a rule group associated with a web ACL and want to submit an UpdateWebACL request to exclude certain rules from that rule group, you must first remove the rule group from the web ACL, the re-insert it again, specifying the excluded rules. For details, see ActivatedRule$ExcludedRules .

Be aware that if you try to add a RATE_BASED rule to a web ACL without setting the rule type when first creating the rule, the UpdateWebACL request will fail because the request tries to add a REGULAR rule (the default rule type) with the specified ID, which does not exist.

For more information about how to use the AWS WAF API to allow or block HTTP requests, see the AWS WAF Developer Guide.