> 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/zec/public-ipv6/assignnetworkinterfaceipv6.md).
# AssignNetworkInterfaceIpv6
## 1. API Description
This API (AssignNetworkInterfaceIpv6) is used to assign IPv6 addresses to a network interface.
{% hint style="info" %}
**Notes**
* This operation is supported only when the stack type of the network interface is `IPv4` and the stack type of the subnet it belongs to is `IPv4_IPv6`.
* If the IPv6 of the subnet is public, the billing-related parameters of the public network need to be specified.
* The committed traffic package size is valid only when the billing cycle is monthly.
{% endhint %}
## 2. Input Parameters
The following request parameter list only provides API request parameters.
| Parameter Name | Required | Type | Description |
| ------------------ | -------- | ---------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| nicId | Yes | String | ID of the network interface to which IPv6 addresses are to be added.
It can be obtained by calling DescribeNetworkInterfaces.
|
| internetChargeType | No | [InternetChargeType](/api-reference/zec/datastructure.md#internetchargetype) | Network billing model.
See InternetChargeType for available values.
If the subnet stack type is IPv4\_IPv6 and the IPv6 access type is Public , this value is required.
|
| bandwidth | No | Integer | Outbound public network bandwidth cap (Mbps). Unit: Mbps.
The value differs with different instance types.
Value range: \[1, +)
|
| packageSize | No | Float | Traffic package size of the public IPv6 address.
Unit: TB.
The value must be 0 or a multiple of 0.1.
This parameter is required when the subnet stack type contains IPv6 that is public and the network billing mode is traffic package billing (ByTrafficPackage).
Value range: \[0.0, +)
|
| clusterId | No | String | ID of the bandwidth cluster specified for the public IPv6 address.
This parameter is required when the subnet stack type contains IPv6 that is public and the network billing mode is bandwidth cluster billing (BandwidthCluster).
|
| rateLimitMode | No | [RateLimitMode](/api-reference/zec/datastructure.md#ratelimitmode) | Rate limit mode.
bandwidth must be specified at the same time for the strict mode (STRICT).
Default value: LOOSE
|
## 3. Output Parameters
| Parameter Name | Type | Description |
| -------------- | ------ | --------------------------------------------------------------------------------------------------------------------- |
| requestId | String | The unique request ID, which is returned for each request.
RequestId is required for locating a problem.
|
## 4. Code Example
{% tabs %}
{% tab title="Example" %}
**1. The network interface is assigned a private IPv6 address.**
```json
POST /api/v2/zec HTTP/1.1
Host: console.zenlayer.com
Content-Type: application/json
X-ZC-Action: AssignNetworkInterfaceIpv6
Request：
{
"nicId": ""
}
Response：
{
"requestId": "T05992D0C-7E8B-4047-B0C0-780F2CD549D3",
"response": {
"requestId": "T05992D0C-7E8B-4047-B0C0-780F2CD549D3"
}
}
```
**2. The network interface is assigned a public IPv6 address, billed by shared bandwidth package, with the bandwidth limit set to 100Mbps.**
```json
POST /api/v2/zec HTTP/1.1
Host: console.zenlayer.com
Content-Type: application/json
X-ZC-Action: AssignNetworkInterfaceIpv6
Request：
{
"nicId": "",
"internetChargeType": "BandwidthCluster",
"bandwidth": 100,
"clusterId": "",
"rateLimitMode": "LOOSE"
}
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 |
| ---------------- | -------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| 400 | INVALID\_NIC\_IPV6\_EXISTS | vNIC already has an IPv6 assigned; operation not allowed. |
| 404 | INVALID\_NIC\_NOT\_FOUND | vNIC does not exist. |
| 400 | INVALID\_NIC\_STATUS | Current vNIC state does not allow this operation. |
| 400 | INVALID\_PARAMETER\_BANDWIDTH\_ERROR | Bandwidth size is below the minimum limit. |
| 400 | INVALID\_PARAMETER\_BANDWIDTH\_EXCEED | Bandwidth size exceeds the upper limit. |
| 400 | INVALID\_RATE\_LIMIT\_MODE\_REQUIRES\_BANDWIDTH | Bandwidth must be specified when the rate limit mode is STRICT. |
| 400 | INVALID\_PARAMETER\_FLOW\_TRAFFIC\_PACKAGE | Data transfer package size is invalid. |
| 400 | INVALID\_PARAMETER\_TRAFFIC\_PACKAGE\_EXCEED | Data traffic package exceeds the maximum limit. |
| 400 | INVALID\_SUBNET\_IPSTACK\_NOT\_SUPPORT | Subnet IP stack type not supported. |
| 409 | INVALID\_SUBNET\_IPV6\_INSUFFICIENT | Insufficient available IPv6 addresses in the subnet. |
| 400 | OPERATION\_DENIED\_INTERNET\_CHARGE\_TYPE\_NOT\_SUPPORT | IP network billing type is not supported. |
| 400 | OPERATION\_DENIED\_NIC\_EXIST\_IPV6 | The vNIC already IPv6 assigned. |
| 400 | OPERATION\_DENIED\_FLOW\_PACKAGE\_NOT\_SUPPORTED\_HOUR\_PERIOD | The current product cycle is based on hourly billing and does not support setting a minimum data package size. |