AWS::EC2::VPCCidrBlock - AWS CloudFormation
SyntaxPropertiesReturn valuesExamples

AWS::EC2::VPCCidrBlock

Associates a CIDR block with your VPC.

You can optionally request an IPv6 CIDR block for the VPC. You can request an Amazon-provided IPv6 CIDR block from Amazon's pool of IPv6 addresses, or an IPv6 CIDR block from an IPv6 address pool that you provisioned through bring your own IP addresses (BYOIP).

For more information, see VPC CIDR blocks in the Amazon VPC User Guide.

Syntax

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

JSON

{
  "Type" : "AWS::EC2::VPCCidrBlock",
  "Properties" : {
      "AmazonProvidedIpv6CidrBlock" : Boolean,
      "CidrBlock" : String,
      "Ipv4IpamPoolId" : String,
      "Ipv4NetmaskLength" : Integer,
      "Ipv6CidrBlock" : String,
      "Ipv6IpamPoolId" : String,
      "Ipv6NetmaskLength" : Integer,
      "Ipv6Pool" : String,
      "VpcId" : String
    }
}

YAML

Type: AWS::EC2::VPCCidrBlock
Properties:
  AmazonProvidedIpv6CidrBlock: Boolean
  CidrBlock: String
  Ipv4IpamPoolId: String
  Ipv4NetmaskLength: Integer
  Ipv6CidrBlock: String
  Ipv6IpamPoolId: String
  Ipv6NetmaskLength: Integer
  Ipv6Pool: String
  VpcId: String

Properties

AmazonProvidedIpv6CidrBlock

Requests an Amazon-provided IPv6 CIDR block with a /56 prefix length for the VPC. You cannot specify the range of IPv6 addresses or the size of the CIDR block.

Required: No

Type: Boolean

Update requires: Replacement

CidrBlock

An IPv4 CIDR block to associate with the VPC.

Required: No

Type: String

Update requires: Replacement

Ipv4IpamPoolId

Associate a CIDR allocated from an IPv4 IPAM pool to a VPC. For more information about Amazon VPC IP Address Manager (IPAM), see What is IPAM? in the Amazon VPC IPAM User Guide.

Required: No

Type: String

Update requires: Replacement

Ipv4NetmaskLength

The netmask length of the IPv4 CIDR you would like to associate from an Amazon VPC IP Address Manager (IPAM) pool. For more information about IPAM, see What is IPAM? in the Amazon VPC IPAM User Guide.

Required: No

Type: Integer

Update requires: Replacement

Ipv6CidrBlock

An IPv6 CIDR block from the IPv6 address pool. You must also specify Ipv6Pool in the request.

To let Amazon choose the IPv6 CIDR block for you, omit this parameter.

Required: No

Type: String

Update requires: Replacement

Ipv6IpamPoolId

Associates a CIDR allocated from an IPv6 IPAM pool to a VPC. For more information about Amazon VPC IP Address Manager (IPAM), see What is IPAM? in the Amazon VPC IPAM User Guide.

Required: No

Type: String

Update requires: Replacement

Ipv6NetmaskLength

The netmask length of the IPv6 CIDR you would like to associate from an Amazon VPC IP Address Manager (IPAM) pool. For more information about IPAM, see What is IPAM? in the Amazon VPC IPAM User Guide.

Required: No

Type: Integer

Update requires: Replacement

Ipv6Pool

The ID of an IPv6 address pool from which to allocate the IPv6 CIDR block.

Required: No

Type: String

Update requires: Replacement

VpcId

The ID of the VPC.

Required: Yes

Type: String

Update requires: Replacement

Return values

Ref

When you pass the logical ID of this resource to the intrinsic Ref function, Ref returns the association ID for the VPC CIDR block.

For more information about using the Ref function, see Ref.

Fn::GetAtt

IpSource

The source that allocated the IP address space. byoip or amazon indicates public IP address space allocated by Amazon or space that you have allocated with Bring your own IP (BYOIP). none indicates private space.

Ipv6AddressAttribute

Public IPv6 addresses are those advertised on the internet from AWS. Private IP addresses are not and cannot be advertised on the internet from AWS.

Examples

Associate an Amazon-provided IPv6 CIDR block

The following example associates an Amazon-provided IPv6 CIDR block (with a prefix length of /56) with the TestVPCIpv6 VPC.

JSON

"Ipv6VPCCidrBlock": {
   "Type": "AWS::EC2::VPCCidrBlock",
   "Properties": {
      "AmazonProvidedIpv6CidrBlock": true,
      "VpcId": { "Ref" : "TestVPCIpv6" }
   }
}

YAML

Ipv6VPCCidrBlock:
   Type: AWS::EC2::VPCCidrBlock
   Properties:
      AmazonProvidedIpv6CidrBlock: true
      VpcId: !Ref TestVPCIpv6

Associate an IPv4 CIDR block and an Amazon-provided IPv6 CIDR block

The following example associates an IPv4 CIDR block and an Amazon-provided IPv6 CIDR block with a VPC. It also outputs the list of IPv4 CIDR block association IDs and IPv6 CIDR blocks that are associated with the VPC.

JSON

{
    "Resources": {
        "VPC": {
            "Type": "AWS::EC2::VPC",
            "Properties": {
                "CidrBlock": "10.0.0.0/24"
            }
        },
        "VpcCidrBlock": {
            "Type": "AWS::EC2::VPCCidrBlock",
            "Properties": {
                "VpcId": {
                    "Ref": "VPC"
                },
                "CidrBlock": "192.0.0.0/24"
            }
        },
        "VpcCidrBlockIpv6": {
            "Type": "AWS::EC2::VPCCidrBlock",
            "Properties": {
                "VpcId": {
                    "Ref": "VPC"
                },
                "AmazonProvidedIpv6CidrBlock": true
            }
        }
    },
    "Outputs": {
        "VpcId": {
            "Value": {
                "Ref": "VPC"
            }
        },
        "PrimaryCidrBlock": {
            "Value": {
                "Fn::GetAtt": [
                    "VPC",
                    "CidrBlock"
                ]
            }
        },
        "Ipv6CidrBlock": {
            "Value": {
                "Fn::Select": [
                    0,
                    {
                        "Fn::GetAtt": [
                            "VPC",
                            "Ipv6CidrBlocks"
                        ]
                    }
                ]
            }
        },
        "CidrBlockAssociation": {
            "Value": {
                "Fn::Select": [
                    0,
                    {
                        "Fn::GetAtt": [
                            "VPC",
                            "CidrBlockAssociations"
                        ]
                    }
                ]
            }
        }
    }
}

YAML

Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/24
  VpcCidrBlock:
    Type: AWS::EC2::VPCCidrBlock
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 192.0.0.0/24
  VpcCidrBlockIpv6:
    Type: AWS::EC2::VPCCidrBlock
    Properties:
      VpcId: !Ref VPC
      AmazonProvidedIpv6CidrBlock: true

Outputs:
  VpcId:
    Value: !Ref VPC
  PrimaryCidrBlock:
    Value: !GetAtt VPC.CidrBlock
  Ipv6CidrBlock:
    Value: !Select [ 0, !GetAtt VPC.Ipv6CidrBlocks ]
  CidrBlockAssociation:
    Value: !Select [ 0, !GetAtt VPC.CidrBlockAssociations ]