> **Experimental**
>
> `@aws-cdk/aws-ec2-alpha` is an [**experimental**](/stability) (alpha) package: its API may change in any release, without a major version bump.
# VPCCidrBlockattributes

Attributes for VPCCidrBlock used for defining a new CIDR Block and also for importing an existing CIDR.

- Stability: [Experimental](/cdk/api/stability.html)
- Source: [`lib/vpc-v2.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0-alpha.0/packages/@aws-cdk/aws-ec2-alpha/lib/vpc-v2.ts#L743)

## Example

```ts
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import * as ec2_alpha from '@aws-cdk/aws-ec2-alpha';
const vPCCidrBlockattributes: ec2_alpha.VPCCidrBlockattributes = {
  amazonProvidedIpv6CidrBlock: false,
  cidrBlock: 'cidrBlock',
  cidrBlockName: 'cidrBlockName',
  ipv4IpamPoolId: 'ipv4IpamPoolId',
  ipv4IpamProvisionedCidrs: ['ipv4IpamProvisionedCidrs'],
  ipv4NetmaskLength: 123,
  ipv6CidrBlock: 'ipv6CidrBlock',
  ipv6IpamPoolId: 'ipv6IpamPoolId',
  ipv6NetmaskLength: 123,
  ipv6Pool: 'ipv6Pool',
};
```

## Properties

- `amazonProvidedIpv6CidrBlock`: boolean = false — Amazon Provided Ipv6.

- `cidrBlock`: string — The secondary IPv4 CIDR Block.

  **Default:** no CIDR block provided

- `cidrBlockName`: string — The secondary IPv4 CIDR Block.

  **Default:** no CIDR block provided

- `ipv4IpamPoolId`: string — IPAM pool for IPv4 address type.

  **Default:** no IPAM pool Id provided for IPv4

- `ipv4IpamProvisionedCidrs`: string[] — IPv4 CIDR provisioned under pool Required to check for overlapping CIDRs after provisioning is complete under IPAM pool.

  **Default:** no IPAM IPv4 CIDR range is provisioned using IPAM

- `ipv4NetmaskLength`: number — Net mask length for IPv4 address type.

  **Default:** no Net mask length configured for IPv4

- `ipv6CidrBlock`: string — The IPv6 CIDR block from the specified IPv6 address pool.

  **Default:** No IPv6 CIDR block associated with VPC.

- `ipv6IpamPoolId`: string — IPAM pool for IPv6 address type.

  **Default:** no IPAM pool Id provided for IPv6

- `ipv6NetmaskLength`: number — Net mask length for IPv6 address type.

  **Default:** no Net mask length configured for IPv6

- `ipv6Pool`: string — The ID of the IPv6 address pool from which to allocate the IPv6 CIDR block.

  **Default:** No BYOIP pool associated with VPC.

  Note: BYOIP Pool ID is different than IPAM Pool ID.