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[ aws . ec2 ]



Modifies the specified VPC attachment.

See also: AWS API Documentation

See 'aws help' for descriptions of global parameters.


--transit-gateway-attachment-id <value>
[--add-subnet-ids <value>]
[--remove-subnet-ids <value>]
[--options <value>]
[--dry-run | --no-dry-run]
[--cli-input-json <value>]
[--generate-cli-skeleton <value>]


--transit-gateway-attachment-id (string)

The ID of the attachment.

--add-subnet-ids (list)

The IDs of one or more subnets to add. You can specify at most one subnet per Availability Zone.



"string" "string" ...

--remove-subnet-ids (list)

The IDs of one or more subnets to remove.



"string" "string" ...

--options (structure)

The new VPC attachment options.

DnsSupport -> (string)

Enable or disable DNS support. The default is enable .

Ipv6Support -> (string)

Enable or disable IPv6 support. The default is enable .

ApplianceModeSupport -> (string)

Enable or disable support for appliance mode. If enabled, a traffic flow between a source and destination uses the same Availability Zone for the VPC attachment for the lifetime of that flow. The default is disable .

Shorthand Syntax:


JSON Syntax:

  "DnsSupport": "enable"|"disable",
  "Ipv6Support": "enable"|"disable",
  "ApplianceModeSupport": "enable"|"disable"

--dry-run | --no-dry-run (boolean)

Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is DryRunOperation . Otherwise, it is UnauthorizedOperation .

--cli-input-json (string) Performs service operation based on the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, the CLI 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.

--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. 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 modify a transit gateway VPC attachment

The following modify-transit-gateway-vpc-attachment example adds a subnet to the specified transit gateway VPC attachment.

aws ec2 modify-transit-gateway-vpc-attachment \
    --transit-gateway-attachment-id tgw-attach-09fbd47ddfEXAMPLE \
    --add-subnet-ids subnet-0e51f45802EXAMPLE


    "TransitGatewayVpcAttachment": {
        "TransitGatewayAttachmentId": "tgw-attach-09fbd47ddfEXAMPLE",
        "TransitGatewayId": "tgw-0560315ccfEXAMPLE",
        "VpcId": "vpc-5eccc927",
        "VpcOwnerId": "111122223333",
        "State": "modifying",
        "SubnetIds": [
        "CreationTime": "2019-08-08T16:47:38.000Z",
        "Options": {
            "DnsSupport": "enable",
            "Ipv6Support": "disable"

For more information, see Transit gateway attachments to a VPC in the Transit Gateways Guide.


TransitGatewayVpcAttachment -> (structure)

Information about the modified attachment.

TransitGatewayAttachmentId -> (string)

The ID of the attachment.

TransitGatewayId -> (string)

The ID of the transit gateway.

VpcId -> (string)

The ID of the VPC.

VpcOwnerId -> (string)

The ID of the Amazon Web Services account that owns the VPC.

State -> (string)

The state of the VPC attachment. Note that the initiating state has been deprecated.

SubnetIds -> (list)

The IDs of the subnets.


CreationTime -> (timestamp)

The creation time.

Options -> (structure)

The VPC attachment options.

DnsSupport -> (string)

Indicates whether DNS support is enabled.

Ipv6Support -> (string)

Indicates whether IPv6 support is disabled.

ApplianceModeSupport -> (string)

Indicates whether appliance mode support is enabled.

Tags -> (list)

The tags for the VPC attachment.


Describes a tag.

Key -> (string)

The key of the tag.

Constraints: Tag keys are case-sensitive and accept a maximum of 127 Unicode characters. May not begin with aws: .

Value -> (string)

The value of the tag.

Constraints: Tag values are case-sensitive and accept a maximum of 256 Unicode characters.