> For the complete documentation index, see [llms.txt](https://docs.console.zenlayer.com/api-reference/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.console.zenlayer.com/api-reference/compute/bmc/elastic-ip/associateeipaddress.md).

# AssociateEipAddress

## 1. API Description

This API (AssociateEipAddress) is used to bind an elastic IP to an instance in the same zone.

{% hint style="info" %} <mark style="color:blue;">**Note**</mark>

* <mark style="color:blue;">Only operations on elastic IPs in</mark> <mark style="color:blue;">`AVAILABLE`</mark> <mark style="color:blue;">status are supported.</mark>
* <mark style="color:blue;">Elastic IPs can only be assigned to instances in the same zone.</mark>
* <mark style="color:blue;">The instance to be assigned an elastic IP should be in status of</mark> <mark style="color:blue;">`RUNNING`</mark><mark style="color:blue;">.</mark>
* <mark style="color:blue;">An instance in gateway mode (automatically enabled for ESXi instances) can only be assigned an IPv4 elastic IP with netmask</mark> <mark style="color:blue;">`<= 29`</mark><mark style="color:blue;">.</mark>
* <mark style="color:blue;">To assign an IPv6 elastic IP, the instance must already have a primary IPv6 address. If the "IPv6 elastic IP and VLAN mutual exclusion" setting is enabled for the project, an instance already in a VLAN cannot be assigned an IPv6 elastic IP.</mark>
* <mark style="color:blue;">The number of elastic IPs of the same type (IPv4/IPv6) bound to an instance is limited. If you need more, please contact Zenlayer Support.</mark>
* <mark style="color:blue;">This API is an async API. A request ID is returned after the request is sent. However, it does not mean the binding has been completed. You can use</mark> [<mark style="color:purple;">`DescribeEipAddresses`</mark>](/api-reference/compute/bmc/elastic-ip/describeeipaddresses.md) <mark style="color:blue;">to query the status of the elastic IP.</mark>
  * <mark style="color:blue;">If the status of the elastic IP is</mark> <mark style="color:blue;">`ASSOCIATING`</mark><mark style="color:blue;">, it means that the elastic IP is being bound. Only query operations are allowed during</mark> <mark style="color:blue;">`ASSOCIATING`</mark><mark style="color:blue;">.</mark>
  * <mark style="color:blue;">If the status of the elastic IP is</mark> <mark style="color:blue;">`ASSOCIATED`</mark><mark style="color:blue;">, it means that the elastic IP has been bound.</mark>
    {% endhint %}

## 2. Input Parameters

The following request parameter list only provides API request parameters.

| Parameter Name | Required | Type   | Description                                                                                                                          |
| -------------- | -------- | ------ | ------------------------------------------------------------------------------------------------------------------------------------ |
| eipId          | Yes      | String | <p>ID of an elastic IP.</p><p>To obtain the elastic IP ID, you can call DescribeEipAddresses and look for eipId in the response.</p> |
| instanceId     | Yes      | String | <p>Instance ID.</p><p>To obtain the instance ID, you can call DescribeInstances and look for instanceId in the response.</p>         |

## 3. Output Parameters

| Parameter Name | Type   | Description                                                                                                           |
| -------------- | ------ | --------------------------------------------------------------------------------------------------------------------- |
| requestId      | String | <p>The unique request ID, which is returned for each request.</p><p>RequestId is required for locating a problem.</p> |

## 4. Code Example

{% tabs %}
{% tab title="Example" %}
**Bind an elastic IP to an instance**

```json
POST /api/v2/bmc HTTP/1.1
Host: console.zenlayer.com
Content-Type: application/json
X-ZC-Action: AssociateEipAddress
<Common Request Params>

Request：
{
    "eipId": "eipId1",
    "instanceId": "instanceId1"
}

Response：
{
  "requestId": "T05992D0C-7E8B-4047-B0C0-780F2CD549D3",
  "response": {  
    "requestId": "T05992D0C-7E8B-4047-B0C0-780F2CD549D3"
  }
}
```

{% endtab %}
{% endtabs %}

## 5. Developer Resources

Zenlayer Cloud API 2.0 integrates [SDKs](/api-reference/api-introduction/toolkit/api-sdk.md)，to make it easier for you to call APIs. More programming languages will be supported.

## 6. Error Codes

The following only lists the error codes related to the API business logic. For other error codes, see [Common Error Codes](/api-reference/api-introduction/instruction/commonerrorcode.md).

| HTTP Status Code | Error Code                                        | Description                                                                                                           |
| ---------------- | ------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| 404              | INVALID\_INSTANCE\_NOT\_FOUND                     | Instance does not exist.                                                                                              |
| 403              | OPERATION\_DENIED\_INSTANCE\_RECYCLED             | The instance is in the recycle bin.                                                                                   |
| 403              | OPERATION\_DENIED\_INSTANCE\_NOT\_RUNNING         | Only operations on instances in RUNNING status are supported.                                                         |
| 404              | INVALID\_EIP\_NOT\_FOUND                          | The specified elastic IP does not exist.                                                                              |
| 403              | OPERATION\_DENIED\_EIP\_ZONE\_NOT\_SAME           | The specified elastic IP is not in the same zone as the instance.                                                     |
| 403              | OPERATION\_DENIED\_EIP\_STATUS\_NOT\_AVAILABLE    | The specified elastic IP state is not available.                                                                      |
| 403              | OPERATION\_DENIED\_EIP\_GATEWAY\_INSTANCE\_ASSIGN | Only IPv4 elastic IPs with netmask <= 29 can be assigned to a gateway mode instance.                                  |
| 403              | OPERATION\_DENIED\_IPV6\_EIP\_VLAN\_MUTEX         | IPv6 elastic IP and VLAN are mutually exclusive. An instance already in a VLAN cannot be assigned an IPv6 elastic IP. |
| 403              | OPERATION\_DENIED\_INSTANCE\_IPV6\_REQUIRED       | An IPv6 address is required on the instance to assign an IPv6 elastic IP.                                             |