---
type: resource-type
title: SubnetCidrBlock
description: aws resource type AWS::EC2::SubnetCidrBlock
name: SubnetCidrBlock
lexicon: aws
resource_type: AWS::EC2::SubnetCidrBlock
---
`AWS::EC2::SubnetCidrBlock`, a resource type of the aws lexicon.

## Properties

- `SubnetId` (`string`, required): The ID of the subnet
- `Id` (`string`, optional): Information about the IPv6 association.
- `IpSource` (`string`, optional): The IP Source of an IPv6 Subnet CIDR Block.
- `Ipv6AddressAttribute` (`string`, optional): The value denoting whether an IPv6 Subnet CIDR Block is public or private.
- `Ipv6CidrBlock` (`string`, optional): The IPv6 network range for the subnet, in CIDR notation. The subnet size must use a /64 prefix length
- `Ipv6IpamPoolId` (`string`, optional): The ID of an IPv6 Amazon VPC IP Address Manager (IPAM) pool from which to allocate, to get the subnet's CIDR
- `Ipv6NetmaskLength` (`number`, optional): The netmask length of the IPv6 CIDR to allocate to the subnet from an IPAM pool

## Attributes

- `Id`
- `IpSource`
- `Ipv6AddressAttribute`