This is the new *CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [AWS CloudFormation User Guide](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::EC2::PrefixList
<a name="aws-resource-ec2-prefixlist"></a>

Specifies a managed prefix list. You can add one or more entries to the prefix list. Each entry consists of a CIDR block and an optional description.

## Syntax
<a name="aws-resource-ec2-prefixlist-syntax"></a>

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

### JSON
<a name="aws-resource-ec2-prefixlist-syntax.json"></a>

```
{
  "Type" : "AWS::EC2::PrefixList",
  "Properties" : {
      "[AddressFamily](#cfn-ec2-prefixlist-addressfamily)" : String,
      "[Entries](#cfn-ec2-prefixlist-entries)" : [ Entry, ... ],
      "[MaxEntries](#cfn-ec2-prefixlist-maxentries)" : Integer,
      "[PrefixListName](#cfn-ec2-prefixlist-prefixlistname)" : String,
      "[Tags](#cfn-ec2-prefixlist-tags)" : [ Tag, ... ]
    }
}
```

### YAML
<a name="aws-resource-ec2-prefixlist-syntax.yaml"></a>

```
Type: AWS::EC2::PrefixList
Properties:
  [AddressFamily](#cfn-ec2-prefixlist-addressfamily): String
  [Entries](#cfn-ec2-prefixlist-entries): 
    - Entry
  [MaxEntries](#cfn-ec2-prefixlist-maxentries): Integer
  [PrefixListName](#cfn-ec2-prefixlist-prefixlistname): String
  [Tags](#cfn-ec2-prefixlist-tags): 
    - Tag
```

## Properties
<a name="aws-resource-ec2-prefixlist-properties"></a>

`AddressFamily`  <a name="cfn-ec2-prefixlist-addressfamily"></a>
The IP address type.  
Valid Values: `IPv4` \$1 `IPv6`  
*Required*: Yes  
*Type*: String  
*Allowed values*: `IPv4 | IPv6`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Entries`  <a name="cfn-ec2-prefixlist-entries"></a>
The entries for the prefix list.  
*Required*: No  
*Type*: Array of [Entry](aws-properties-ec2-prefixlist-entry.md)  
*Minimum*: `0`  
*Maximum*: `100`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`MaxEntries`  <a name="cfn-ec2-prefixlist-maxentries"></a>
The maximum number of entries for the prefix list. You can't modify the entries and the size of a prefix list at the same time.  
This property is required when you create a prefix list.  
*Required*: Conditional  
*Type*: Integer  
*Minimum*: `1`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`PrefixListName`  <a name="cfn-ec2-prefixlist-prefixlistname"></a>
A name for the prefix list.  
Constraints: Up to 255 characters in length. The name cannot start with `com.amazonaws`.  
*Required*: Yes  
*Type*: String  
*Minimum*: `1`  
*Maximum*: `255`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Tags`  <a name="cfn-ec2-prefixlist-tags"></a>
The tags for the prefix list.  
*Required*: No  
*Type*: Array of [Tag](aws-properties-ec2-prefixlist-tag.md)  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

## Return values
<a name="aws-resource-ec2-prefixlist-return-values"></a>

### Ref
<a name="aws-resource-ec2-prefixlist-return-values-ref"></a>

When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns the ID of the prefix list.

For more information about using the `Ref` function, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html).

### Fn::GetAtt
<a name="aws-resource-ec2-prefixlist-return-values-fn--getatt"></a>

The `Fn::GetAtt` intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.

For more information about using the `Fn::GetAtt` intrinsic function, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-getatt.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-getatt.html).

#### 
<a name="aws-resource-ec2-prefixlist-return-values-fn--getatt-fn--getatt"></a>

`Arn`  <a name="Arn-fn::getatt"></a>
The ARN of the prefix list. For example, `arn:aws:ec2:us-east-1:123456789012:prefix-list/pl-0123123123123abcd`.

`OwnerId`  <a name="OwnerId-fn::getatt"></a>
The ID of the owner of the prefix list. For example, `123456789012`.

`PrefixListId`  <a name="PrefixListId-fn::getatt"></a>
The ID of the prefix list. For example, `pl-0123123123123abcd`.

`Version`  <a name="Version-fn::getatt"></a>
The version of the prefix list. For example, `1`.

## Examples
<a name="aws-resource-ec2-prefixlist--examples"></a>

### Create a prefix list
<a name="aws-resource-ec2-prefixlist--examples--Create_a_prefix_list"></a>

The following example creates an IPv4 prefix list with a maximum of 10 entries, and creates 2 entries in the prefix list.

#### JSON
<a name="aws-resource-ec2-prefixlist--examples--Create_a_prefix_list--json"></a>

```
{
    "Resources": {
        "NewPrefixList": {
            "Type": "AWS::EC2::PrefixList",
            "Properties": {
                "PrefixListName": "vpc-1-servers",
                "AddressFamily": "IPv4",
                "MaxEntries": 10,
                "Entries": [
                    {
                        "Cidr": "10.0.0.5/32",
                        "Description": "Server 1"
                    },
                    {
                        "Cidr": "10.0.0.10/32",
                        "Description": "Server 2"
                    }
                ],
                "Tags": [
                    {
                        "Key": "Name",
                        "Value": "VPC-1-Servers"
                    }
                ]
            }
        }
    }
}
```

#### YAML
<a name="aws-resource-ec2-prefixlist--examples--Create_a_prefix_list--yaml"></a>

```
Resources:
  NewPrefixList:
    Type: AWS::EC2::PrefixList
    Properties:
      PrefixListName: "vpc-1-servers"
      AddressFamily: "IPv4"
      MaxEntries: 10
      Entries:
        - Cidr: "10.0.0.5/32"
          Description: "Server 1"
        - Cidr: "10.0.0.10/32"
          Description: "Server 2"
      Tags:
        - Key: "Name"
          Value: "VPC-1-Servers"
```

# AWS::EC2::PrefixList Entry
<a name="aws-properties-ec2-prefixlist-entry"></a>

An entry for a prefix list.

## Syntax
<a name="aws-properties-ec2-prefixlist-entry-syntax"></a>

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

### JSON
<a name="aws-properties-ec2-prefixlist-entry-syntax.json"></a>

```
{
  "[Cidr](#cfn-ec2-prefixlist-entry-cidr)" : String,
  "[Description](#cfn-ec2-prefixlist-entry-description)" : String
}
```

### YAML
<a name="aws-properties-ec2-prefixlist-entry-syntax.yaml"></a>

```
  [Cidr](#cfn-ec2-prefixlist-entry-cidr): String
  [Description](#cfn-ec2-prefixlist-entry-description): String
```

## Properties
<a name="aws-properties-ec2-prefixlist-entry-properties"></a>

`Cidr`  <a name="cfn-ec2-prefixlist-entry-cidr"></a>
The CIDR block.  
*Required*: Yes  
*Type*: String  
*Minimum*: `1`  
*Maximum*: `46`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Description`  <a name="cfn-ec2-prefixlist-entry-description"></a>
A description for the entry.  
Constraints: Up to 255 characters in length.  
*Required*: No  
*Type*: String  
*Minimum*: `0`  
*Maximum*: `255`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

# AWS::EC2::PrefixList Tag
<a name="aws-properties-ec2-prefixlist-tag"></a>

Specifies a tag. For more information, see [Resource tags](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-resource-tags.html).

## Syntax
<a name="aws-properties-ec2-prefixlist-tag-syntax"></a>

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

### JSON
<a name="aws-properties-ec2-prefixlist-tag-syntax.json"></a>

```
{
  "[Key](#cfn-ec2-prefixlist-tag-key)" : String,
  "[Value](#cfn-ec2-prefixlist-tag-value)" : String
}
```

### YAML
<a name="aws-properties-ec2-prefixlist-tag-syntax.yaml"></a>

```
  [Key](#cfn-ec2-prefixlist-tag-key): String
  [Value](#cfn-ec2-prefixlist-tag-value): String
```

## Properties
<a name="aws-properties-ec2-prefixlist-tag-properties"></a>

`Key`  <a name="cfn-ec2-prefixlist-tag-key"></a>
The tag key.  
*Required*: Yes  
*Type*: String  
*Minimum*: `1`  
*Maximum*: `128`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Value`  <a name="cfn-ec2-prefixlist-tag-value"></a>
The tag value.  
*Required*: No  
*Type*: String  
*Maximum*: `256`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

## Examples
<a name="aws-properties-ec2-prefixlist-tag--examples"></a>

### 
<a name="aws-properties-ec2-prefixlist-tag--examples--"></a>

This example specifies two tags for the prefix list.

#### JSON
<a name="aws-properties-ec2-prefixlist-tag--examples----json"></a>

```
"Tags" : [
   {
      "Key" : "key1",
      "Value" : "value1"
   },
   {
      "Key" : "key2",
      "Value" : "value2"
   }
]
```

#### YAML
<a name="aws-properties-ec2-prefixlist-tag--examples----yaml"></a>

```
Tags: 
  - Key: "key1"
    Value: "value1"
  - Key: "key2"
    Value: "value2"
```