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::LaunchTemplate Ipv4PrefixSpecification

Specifies an IPv4 prefix for a network interface.
`Ipv4PrefixSpecification` is a property of [AWS::EC2::LaunchTemplate NetworkInterface](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ec2-launchtemplate-networkinterface.html).
## Syntax

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

```
{
 "[Ipv4Prefix](#cfn-ec2-launchtemplate-ipv4prefixspecification-ipv4prefix)" : {{String}}
}
```
### YAML

```
 [Ipv4Prefix](#cfn-ec2-launchtemplate-ipv4prefixspecification-ipv4prefix): {{String}}
```
## Properties

`Ipv4Prefix` 
The IPv4 prefix. For information, see [ Assigning prefixes to network interfaces](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-prefix-eni.html) in the *Amazon EC2 User Guide*. 
*Required*: No 
*Type*: String 
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