> 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/bmc/cidr-block/createipv4block.md).

# CreateIpv4Block

## 1. API Description

This API (CreateIpv4Block) is used to create one or more IPv4 CIDR blocks.

#### Prerequisites

* Query stock: call [`DescribeAvailableIpv4Resources`](/api-reference/bmc/cidr-block/describeavailableipv4resources.md) to check available resources.
* Cost estimation: know of CIDR block pricing. See [Billing Method](https://docs.console.zenlayer.com/welcome/pricing/bare-metal-cloud-pricing/billing-method#cidr-block) for more details.

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

* <mark style="color:blue;">If you create a subscription CIDR block, the amount required will be pre-deducted. If the balance is insufficient, the request will fail. If you create a pay-as-you-go CIDR block, please ensure your account balance is sufficient before calling this API.</mark>
* <mark style="color:blue;">Vouchers can be used for fee deduction in instance creation. See</mark> [<mark style="color:purple;">Vouchers</mark>](https://docs.console.zenlayer.com/welcome/platform/billing-center/vouchers) <mark style="color:blue;">for more details.</mark>
* <mark style="color:blue;">This API is an async API. A CIDR block ID list is returned after the creation request is sent. However, it does not mean the creation has been completed. The status of the CIDR block will be</mark> <mark style="color:blue;">`CREATING`</mark> <mark style="color:blue;">during the creation. You can use</mark> [<mark style="color:blue;">DescribeCidrBlocks</mark>](/api-reference/bmc/cidr-block/describecidrblocks.md) <mark style="color:blue;">to query the status of the CIDR block. If the status changes from</mark> <mark style="color:blue;">`Creating`</mark> <mark style="color:blue;">to</mark> <mark style="color:blue;">`Available`</mark><mark style="color:blue;">, it means that the CIDR block has been created successfully;</mark> <mark style="color:blue;">`CREATE_FAILED`</mark> <mark style="color:blue;">means the CIDR block has been created failed. Any operations on the instances are not allowed while creating.</mark>
  {% endhint %}

## 2. Input Parameters

The following request parameter list only provides API request parameters.

| Parameter Name   | Required | Type                                                                 | Description                                                                                                                                                                                                              |
| ---------------- | -------- | -------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| zoneId           | Yes      | String                                                               | Zone ID to which the CIDR blocks belong.                                                                                                                                                                                 |
| chargeType       | Yes      | [ChargeType](/api-reference/bmc/datastructure.md#chargetype)         | <p>CIDR block pricing model .</p><p>PREPAID: subscription POSTPAID: pay-as-you-go</p>                                                                                                                                    |
| netmask          | Yes      | Integer                                                              | <p>Netmasks you want to purchase.</p><p>Value range: \[1,32].</p><p>You can find the available netmasks in the response by calling DescribeAvailableIpv4Resource .</p><p>Value range: \[1, 32]</p>                       |
| name             | No       | String                                                               | <p>CIDR block name to be displayed.</p><p>This parameter can contain up to 64 characters.</p>                                                                                                                            |
| cidrType         | No       | [CidrBlockType](/api-reference/bmc/datastructure.md#cidrblocktype)   | <p>CIDR block type.</p><p>Default value: BGP</p>                                                                                                                                                                         |
| chargePrepaid    | No       | [ChargePrepaid](/api-reference/bmc/datastructure.md#chargeprepaid)   | Details of the monthly subscription, including the purchase period, auto-renewal. It is required if the chargeType is PREPAID .                                                                                          |
| amount           | No       | Integer                                                              | <p>Quantity of IPv4 CIDR blocks you want to purchase.</p><p>Default value: 1.</p><p>Value range: \[1, +)</p>                                                                                                             |
| resourceGroupId  | No       | String                                                               | <p>Resource group ID where the CIDR blocks reside.</p><p>If an available VLAN exists in the specified zone, this parameter will be ignored. The created CIDR blocks will be added to the resource group of the VLAN.</p> |
| marketingOptions | No       | [MarketingInfo](/api-reference/bmc/datastructure.md#marketinginfo)   | Information on marketing campaigns.                                                                                                                                                                                      |
| tags             | No       | [TagAssociation](/api-reference/bmc/datastructure.md#tagassociation) | <p>Bound tags when creating resources.</p><p>Tag keys must be unique.</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> |
| orderNumber    | String          | Number of order.                                                                                                      |
| cidrBlockIds   | Array of String | List of CIDR block IDs.                                                                                               |

## 4. Code Example

{% tabs %}
{% tab title="Example" %}
Create a postpaid IPv4 CIDR block `example1` with the netmask of `29` in `IST-B`, belonging to `Default Resource Group`.

```json
POST /api/v2/bmc HTTP/1.1
Host: console.zenlayer.com
Content-Type: application/json
X-ZC-Action: CreateIpv4Block
<Common Request Params>

Request:
{
  "zoneId": "IST-B",
  "name": "example1",
  "chargeType": "POSTPAID",
  "netmask": 29
}

Response:
{
  "requestId": "T135376EE-7090-4773-B81E-7FB38358B656",
  "response": {
    "requestId": "T135376EE-7090-4773-B81E-7FB38358B656",
    "orderNumber": "orderNum",
    "cidrBlockIds": [
      "cidrBlockId"
    ]
  }
}
```

{% 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              | OPERATION\_DENIED\_NETMASK\_OUT\_OF\_STOCK | Netmask out of stock. |
| 404              | INVALID\_ZONE\_NOT\_FOUND                  | Zone not found.       |