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# AWS::NetworkFirewall::RuleGroup StatelessRule
<a name="aws-properties-networkfirewall-rulegroup-statelessrule"></a>

A single stateless rule. This is used in `StatelessRulesAndCustomActions`.

## Syntax
<a name="aws-properties-networkfirewall-rulegroup-statelessrule-syntax"></a>

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

### JSON
<a name="aws-properties-networkfirewall-rulegroup-statelessrule-syntax.json"></a>

```
{
  "[Priority](#cfn-networkfirewall-rulegroup-statelessrule-priority)" : Integer,
  "[RuleDefinition](#cfn-networkfirewall-rulegroup-statelessrule-ruledefinition)" : RuleDefinition
}
```

### YAML
<a name="aws-properties-networkfirewall-rulegroup-statelessrule-syntax.yaml"></a>

```
  [Priority](#cfn-networkfirewall-rulegroup-statelessrule-priority): Integer
  [RuleDefinition](#cfn-networkfirewall-rulegroup-statelessrule-ruledefinition): 
    RuleDefinition
```

## Properties
<a name="aws-properties-networkfirewall-rulegroup-statelessrule-properties"></a>

`Priority`  <a name="cfn-networkfirewall-rulegroup-statelessrule-priority"></a>
Indicates the order in which to run this rule relative to all of the rules that are defined for a stateless rule group. Network Firewall evaluates the rules in a rule group starting with the lowest priority setting. You must ensure that the priority settings are unique for the rule group.   
Each stateless rule group uses exactly one `StatelessRulesAndCustomActions` object, and each `StatelessRulesAndCustomActions` contains exactly one `StatelessRules` object. To ensure unique priority settings for your rule groups, set unique priorities for the stateless rules that you define inside any single `StatelessRules` object.  
You can change the priority settings of your rules at any time. To make it easier to insert rules later, number them so there's a wide range in between, for example use 100, 200, and so on.   
*Required*: Yes  
*Type*: Integer  
*Minimum*: `1`  
*Maximum*: `65535`  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`RuleDefinition`  <a name="cfn-networkfirewall-rulegroup-statelessrule-ruledefinition"></a>
Defines the stateless 5-tuple packet inspection criteria and the action to take on a packet that matches the criteria.   
*Required*: Yes  
*Type*: [RuleDefinition](aws-properties-networkfirewall-rulegroup-ruledefinition.md)  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)