This is the new *Amazon CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [Amazon CloudFormation User Guide](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::EC2::TransitGatewayConnect TransitGatewayConnectOptions
<a name="aws-properties-ec2-transitgatewayconnect-transitgatewayconnectoptions"></a>

Describes the Connect attachment options.

## Syntax
<a name="aws-properties-ec2-transitgatewayconnect-transitgatewayconnectoptions-syntax"></a>

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

### JSON
<a name="aws-properties-ec2-transitgatewayconnect-transitgatewayconnectoptions-syntax.json"></a>

```
{
  "[Protocol](#cfn-ec2-transitgatewayconnect-transitgatewayconnectoptions-protocol)" : String
}
```

### YAML
<a name="aws-properties-ec2-transitgatewayconnect-transitgatewayconnectoptions-syntax.yaml"></a>

```
  [Protocol](#cfn-ec2-transitgatewayconnect-transitgatewayconnectoptions-protocol): String
```

## Properties
<a name="aws-properties-ec2-transitgatewayconnect-transitgatewayconnectoptions-properties"></a>

`Protocol`  <a name="cfn-ec2-transitgatewayconnect-transitgatewayconnectoptions-protocol"></a>
The tunnel protocol.  
*Required*: No  
*Type*: String  
*Allowed values*: `gre`  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)