[ aws . ec2 ]



Associates a CIDR block with your subnet. You can only associate a single IPv6 CIDR block with your subnet. An IPv6 CIDR block must have a prefix length of /64.

See also: AWS API Documentation

See ‘aws help’ for descriptions of global parameters.


--subnet-id <value>
--ipv6-cidr-block <value>
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]


--subnet-id (string)

The ID of your subnet.

--ipv6-cidr-block (string)

The IPv6 CIDR block for your subnet. The subnet must have a /64 prefix length.

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See ‘aws help’ for descriptions of global parameters.


To associate an IPv6 CIDR block with a subnet

This example associates an IPv6 CIDR block with the specified subnet.


aws ec2 associate-subnet-cidr-block --subnet-id subnet-5f46ec3b --ipv6-cidr-block 2001:db8:1234:1a00::/64


  "SubnetId": "subnet-5f46ec3b",
  "Ipv6CidrBlockAssociation": {
      "Ipv6CidrBlock": "2001:db8:1234:1a00::/64",
      "AssociationId": "subnet-cidr-assoc-3aa54053",
      "Ipv6CidrBlockState": {
          "State": "associating"


Ipv6CidrBlockAssociation -> (structure)

Information about the IPv6 CIDR block association.

AssociationId -> (string)

The association ID for the CIDR block.

Ipv6CidrBlock -> (string)

The IPv6 CIDR block.

Ipv6CidrBlockState -> (structure)

Information about the state of the CIDR block.

State -> (string)

The state of a CIDR block.

StatusMessage -> (string)

A message about the status of the CIDR block, if applicable.

SubnetId -> (string)

The ID of the subnet.