# ModifyVpnConnection
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Modifies the customer gateway or the target gateway of an Amazon Site-to-Site VPN connection. To modify the target gateway, the following migration options are available:
+ An existing virtual private gateway to a new virtual private gateway
+ An existing virtual private gateway to a transit gateway
+ An existing transit gateway to a new transit gateway
+ An existing transit gateway to a virtual private gateway

Before you perform the migration to the new gateway, you must configure the new gateway. Use [CreateVpnGateway](API_CreateVpnGateway.md) to create a virtual private gateway, or [CreateTransitGateway](API_CreateTransitGateway.md) to create a transit gateway.

This step is required when you migrate from a virtual private gateway with static routes to a transit gateway. 

You must delete the static routes before you migrate to the new gateway.

Keep a copy of the static route before you delete it. You will need to add back these routes to the transit gateway after the VPN connection migration is complete.

After you migrate to the new gateway, you might need to modify your VPC route table. Use [CreateRoute](API_CreateRoute.md) and [DeleteRoute](API_DeleteRoute.md) to make the changes described in [Update VPC route tables](https://docs.amazonaws.cn/vpn/latest/s2svpn/modify-vpn-target.html#step-update-routing) in the * Amazon Site-to-Site VPN User Guide*.

When the new gateway is a transit gateway, modify the transit gateway route table to allow traffic between the VPC and the Amazon Site-to-Site VPN connection. Use [CreateTransitGatewayRoute](API_CreateTransitGatewayRoute.md) to add the routes.

 If you deleted VPN static routes, you must add the static routes to the transit gateway route table.

After you perform this operation, the VPN endpoint's IP addresses on the Amazon side and the tunnel options remain intact. Your Amazon Site-to-Site VPN connection will be temporarily unavailable for a brief period while we provision the new endpoints.

## Request Parameters
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The following parameters are for this specific action. For more information about required and optional parameters that are common to all actions, see [Common Query Parameters](CommonParameters.md).

 **CustomerGatewayId**   
The ID of the customer gateway at your end of the VPN connection.  
Type: String  
Required: No

 **DryRun**   
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`.  
Type: Boolean  
Required: No

 **TransitGatewayId**   
The ID of the transit gateway.  
Type: String  
Required: No

 **VpnConnectionId**   
The ID of the VPN connection.  
Type: String  
Required: Yes

 **VpnGatewayId**   
The ID of the virtual private gateway at the Amazon side of the VPN connection.  
Type: String  
Required: No

## Response Elements
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The following elements are returned by the service.

 **requestId**   
The ID of the request.  
Type: String

 **vpnConnection**   
Information about the VPN connection.  
Type: [VpnConnection](API_VpnConnection.md) object

## Errors
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For information about the errors that are common to all actions, see [Common client error codes](errors-overview.md#CommonErrors).

## See Also
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For more information about using this API in one of the language-specific Amazon SDKs, see the following:
+  [Amazon Command Line Interface V2](https://docs.amazonaws.cn/goto/cli2/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for .NET V4](https://docs.amazonaws.cn/goto/DotNetSDKV4/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for C\$1\$1](https://docs.amazonaws.cn/goto/SdkForCpp/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for Go v2](https://docs.amazonaws.cn/goto/SdkForGoV2/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for Java V2](https://docs.amazonaws.cn/goto/SdkForJavaV2/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for JavaScript V3](https://docs.amazonaws.cn/goto/SdkForJavaScriptV3/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for Kotlin](https://docs.amazonaws.cn/goto/SdkForKotlin/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for PHP V3](https://docs.amazonaws.cn/goto/SdkForPHPV3/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for Python](https://docs.amazonaws.cn/goto/boto3/ec2-2016-11-15/ModifyVpnConnection) 
+  [Amazon SDK for Ruby V3](https://docs.amazonaws.cn/goto/SdkForRubyV3/ec2-2016-11-15/ModifyVpnConnection)