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

Common properties for creating a Transit Gateway resource.

- Stability: [Experimental](/cdk/api/stability.html)
- Source: [`lib/transit-gateway.ts`](https://github.com/aws/aws-cdk/blob/v2.273.0-alpha.0/packages/@aws-cdk/aws-ec2-alpha/lib/transit-gateway.ts#L75)

## Example

```ts
const transitGateway = new TransitGateway(this, 'MyTransitGateway', {
  defaultRouteTableAssociation: false,
  defaultRouteTablePropagation: false,
});
```

## Properties

- `amazonSideAsn`: number = undefined, 64512 is assigned by CloudFormation. — A private Autonomous System Number (ASN) for the Amazon side of a BGP session.

  The range is 64512 to 65534 for 16-bit ASNs.

  **Default:** undefined, 64512 is assigned by CloudFormation.

- `autoAcceptSharedAttachments`: boolean = disable (false) — Enable or disable automatic acceptance of cross-account attachment requests.

- `defaultRouteTableAssociation`: boolean = enable (true) — Enable or disable automatic association with the default association route table.

- `defaultRouteTablePropagation`: boolean = enable (true) — Enable or disable automatic propagation of routes to the default propagation route table.

- `description`: string = no description — The description of the transit gateway.

- `dnsSupport`: boolean = enable (true) — Enable or disable DNS support.

  If dnsSupport is enabled on a VPC Attachment, this also needs to be enabled for the feature to work.
  Otherwise the resources will still deploy but the feature will not work.

- `securityGroupReferencingSupport`: boolean = disable (false) — Enable or disable security group referencing support.

  If securityGroupReferencingSupport is enabled on a VPC Attachment, this also needs to be enabled for the feature to work.
  Otherwise the resources will still deploy but the feature will not work.

- `transitGatewayCidrBlocks`: string[] = none — The transit gateway CIDR blocks.

- `transitGatewayName`: string = Assigned by CloudFormation. — Physical name of this Transit Gateway.

## Used as props by

- [`TransitGateway`](/v2/docs/@aws-cdk_aws-ec2-alpha.TransitGateway)