# IP address types for REST APIs in API Gateway
<a name="api-gateway-ip-address-type"></a>

When you create an API, you specify the type of IP addresses that can invoke your API. You can choose IPv4 to resolve IPv4 addresses to invoke your API, or you can choose dualstack to allow both IPv4 and IPv6 addresses to invoke your API. We recommend that you set the IP address type to dualstack to alleviate IP space exhaustion or for your security posture. For more information about the benefits of a dualstack IP address type, see [IPv6 on AWS](https://docs.aws.amazon.com/whitepapers/latest/ipv6-on-aws/internet-protocol-version-6.html).

To restrict your API to only IPv6 traffic, you can create a resource policy and restrict the source IP addresses to only IPv6 ranges. You can change the IP address type by updating the API’s configuration. This change will take effect immediately, and you don't need to redeploy your API. For more information, see [Example: Deny API traffic based on source IP address or range](apigateway-resource-policies-examples.md#apigateway-resource-policies-source-ip-address-example)

## Considerations for IP address types
<a name="api-gateway-ip-address-type-considerations"></a>

The following considerations might impact your use of IP address types:
+ The default IP address type for all Regional and edge-optimized APIs is IPv4.
+ Private APIs can only have a dualstack IP address type.
+ If you change the IP address type for an existing API from IPv4 to dualstack, confirm that any policies controlling access to your APIs have been updated to account for IPv6 calls. When you change the IP address type, the change takes effect immediately. 
+ If you migrate the endpoint type of an API from Regional or edge-optimized to private, API Gateway changes the IP address type to dualstack. For more information, see [Change a public or private API endpoint type in API Gateway](apigateway-api-migration.md).
+ If you migrate the endpoint type of an API from private to Regional, you must set the IP address type to dualstack. After the endpoint migration is complete, you can change the IP address type to IPv4. For more information, see [Change a public or private API endpoint type in API Gateway](apigateway-api-migration.md).
+ Your API can be mapped to a custom domain name with a different IP address type than your API. If you disable your default API endpoint, this might affect how callers can invoke your API.
+ You can't use an external definition file to configure your API's IP address type.

# Change the IP address type of a REST API
<a name="api-gateway-ip-address-type-change"></a>

You can change the IP address type by updating the API’s configuration. You can update the API's configuration by using the AWS Management Console, the AWS CLI, CloudFormation, or an AWS SDK. If you change the API’s IP address type, you don't redeploy your API for the changes to take effect. Before you change the IP address type, confirm that any policies controlling access to your APIs have been updated to account for IPv6 calls.

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#### [ AWS Management Console ]

**To change the IP address type of a REST API**

1. Sign in to the API Gateway console at [https://console.aws.amazon.com/apigateway](https://console.aws.amazon.com/apigateway).

1. Choose a REST API.

1. Choose **API settings**, and then choose **Edit**.

1. For IP address type, select either **IPv4** or **Dualstack**.

1. Choose **Save changes**.

   The change to your API's configuration will take effect immediately.

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#### [ AWS CLI ]

The following [update-rest-api](https://docs.aws.amazon.com/cli/latest/reference/apigateway/update-rest-api.html) command updates an API to have an IP address type of dualstack:

```
aws apigateway update-rest-api \
    --rest-api-id abcd1234 \
    --patch-operations "op='replace',path='/endpointConfiguration/ipAddressType',value='dualstack'"
```

The output will look like the following:

```
{
    "id": "abcd1234",
    "name": "MyAPI",
    "description": "My API with a dualstack IP address type",
    "createdDate": "2025-02-04T11:47:06-08:00",
    "apiKeySource": "HEADER",
    "endpointConfiguration": {
        "types": [
            "REGIONAL"
        ],
        "ipAddressType": "dualstack"
    },
    "tags": {},
    "disableExecuteApiEndpoint": false,
    "rootResourceId": "efg456"
}
```

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