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# AWS::EC2::TransitGatewayMulticastDomain
<a name="aws-resource-ec2-transitgatewaymulticastdomain"></a>

Creates a multicast domain using the specified transit gateway.

The transit gateway must be in the available state before you create a domain.

## Syntax
<a name="aws-resource-ec2-transitgatewaymulticastdomain-syntax"></a>

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

### JSON
<a name="aws-resource-ec2-transitgatewaymulticastdomain-syntax.json"></a>

```
{
  "Type" : "AWS::EC2::TransitGatewayMulticastDomain",
  "Properties" : {
      "[Options](#cfn-ec2-transitgatewaymulticastdomain-options)" : Options,
      "[Tags](#cfn-ec2-transitgatewaymulticastdomain-tags)" : [ Tag, ... ],
      "[TransitGatewayId](#cfn-ec2-transitgatewaymulticastdomain-transitgatewayid)" : String
    }
}
```

### YAML
<a name="aws-resource-ec2-transitgatewaymulticastdomain-syntax.yaml"></a>

```
Type: AWS::EC2::TransitGatewayMulticastDomain
Properties:
  [Options](#cfn-ec2-transitgatewaymulticastdomain-options): 
    Options
  [Tags](#cfn-ec2-transitgatewaymulticastdomain-tags): 
    - Tag
  [TransitGatewayId](#cfn-ec2-transitgatewaymulticastdomain-transitgatewayid): String
```

## Properties
<a name="aws-resource-ec2-transitgatewaymulticastdomain-properties"></a>

`Options`  <a name="cfn-ec2-transitgatewaymulticastdomain-options"></a>
The options for the transit gateway multicast domain.  
+ AutoAcceptSharedAssociations (enable \$1 disable)
+ Igmpv2Support (enable \$1 disable)
+ StaticSourcesSupport (enable \$1 disable)
*Required*: No  
*Type*: [Options](aws-properties-ec2-transitgatewaymulticastdomain-options.md)  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Tags`  <a name="cfn-ec2-transitgatewaymulticastdomain-tags"></a>
The tags for the transit gateway multicast domain.  
*Required*: No  
*Type*: Array of [Tag](aws-properties-ec2-transitgatewaymulticastdomain-tag.md)  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`TransitGatewayId`  <a name="cfn-ec2-transitgatewaymulticastdomain-transitgatewayid"></a>
The ID of the transit gateway.  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

## Return values
<a name="aws-resource-ec2-transitgatewaymulticastdomain-return-values"></a>

### Ref
<a name="aws-resource-ec2-transitgatewaymulticastdomain-return-values-ref"></a>

When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns the transit gateway multicast domain ID. For example: `tgw-mcast-domain-000fb24d04EXAMPLE`.

### Fn::GetAtt
<a name="aws-resource-ec2-transitgatewaymulticastdomain-return-values-fn--getatt"></a>

The `Fn::GetAtt` intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.

For more information about using the `Fn::GetAtt` intrinsic function, see [https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-getatt.html](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-getatt.html).

#### 
<a name="aws-resource-ec2-transitgatewaymulticastdomain-return-values-fn--getatt-fn--getatt"></a>

`CreationTime`  <a name="CreationTime-fn::getatt"></a>
The time the multicast domain was created.

`State`  <a name="State-fn::getatt"></a>
The state of the multicast domain.

`TransitGatewayMulticastDomainArn`  <a name="TransitGatewayMulticastDomainArn-fn::getatt"></a>
The Amazon Resource Name (ARN) of the multicast domain.

`TransitGatewayMulticastDomainId`  <a name="TransitGatewayMulticastDomainId-fn::getatt"></a>
The ID of the multicast domain.

## See also
<a name="aws-resource-ec2-transitgatewaymulticastdomain--seealso"></a>
+ [CreateTransitGatewayMulticastDomain](https://docs.amazonaws.cn/AWSEC2/latest/APIReference/API_CreateTransitGatewayMulticastDomain.html) in the *Amazon EC2 API Reference*