# CreateSubnet ## 1. API Description This API (CreateSubnet) is used to create a subnet under a VPC. {% hint style="info" %} **Note** * The quantity of subnets you can create under one VPC is limited. The IP range of the subnet under a VPC should be a subset of the VPC IP range. * IP ranges of subnets under the same VPC cannot be overlapped. * Call [**`DescribeSubnetRegions`**](/api-reference/compute/zec/vpc-network/describesubnetregions.md) to query regions supporting subnet creation. {% endhint %} ## 2. Input Parameters The following request parameter list only provides API request parameters. | Parameter Name | Required | Type | Description | | ---------------- | -------- | ------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | vpcId | Yes | String | VPC ID. | | name | Yes | String |

Subnet name to be displayed.

This parameter must start and end with a number or a letter, containing 2 to 63 characters. Only letters, numbers, - and periods (.) are supported.

| | regionId | Yes | String | Region ID. | | stackType | Yes | [SubnetStackType](/api-reference/compute/zec/datastructure.md#subnetstacktype) | Subnet IP stack type. | | cidrBlock | No | String |

CIDR block of the subnet.

If the specified stack type ( stackType ) includes IPv4, this field is required. The specified CIDR block must fall within the VPC’s CIDR range.

| | ipv6Type | No | [IPv6Type](/api-reference/compute/zec/datastructure.md#ipv6type) |

Subnet IPv6 type.

If the specified stack type ( stackType ) includes IPv6, this field is required.

| | dhcpOptionsSetId | No | String | DHCP options set to be associated. | | ipv6CidrBlockId | No | String |

ID of the public IPv6 CIDR block.

This field can only be specified when ipv6Type is Public.

If not specified, it will be allocated from the system's default IP pool.

| | ipv6MaskLength | No | Integer |

The size of the IPv6 CIDR prefix assigned to the instance.

This parameter must be used together with the ipv6CidrBlockId parameter.

The default value is 96 if not explicitly provided.

The minimum value must be greater than or equal to the prefix of the specified ipv6CidrBlockId, and the maximum value cannot exceed 96.

Value range: \[-, 96]

| ## 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.

| | subnetId | String | Subnet ID. | ## 4. Code Example {% tabs %} {% tab title="Example" %} **Create a subnet under a VPC.** 
POST /api/v2/zec HTTP/1.1
Host: console.zenlayer.com
Content-Type: application/json
X-ZC-Action: CreateSubnet


Request:
{
  "vpcId": "xxxx",
  "regionId": "xxx",
  "stackType": "IPv4_IPv6",
  "ipv6Type": "Public",
  "name": "XXX",
  "cidrBlock": "10.0.0.0/9"
}

Response:
{
  "requestId": "TBFC01FCF-6439-4530-ADBC-16809F0C3E8F",
  "response": {
    "requestId": "TBFC01FCF-6439-4530-ADBC-16809F0C3E8F",
    "subnetId": "xxxx"
  }
}
{% 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\_CIDR\_BLOCK\_FORMAT | Invalid CIDR block format. | | 400 | INVALID\_CIDR\_BLOCK\_NOT\_EMPTY | CIDR block cannot be empty. | | 400 | INVALID\_CIDR\_BLOCK\_NOT\_LAN\_IP | CIDR block must be a private IP range. | | 400 | INVALID\_CIDR\_BLOCK\_STATUS | The CIDR block state is invalid. | | 404 | INVALID\_CIDR\_IPV6\_NOT\_FOUND | IPv6 CIDR block does not exist | | 400 | INVALID\_CIDR\_IPV6\_ONLY | IPv6 stack type is specified only. | | 400 | INVALID\_CIDR\_REGION\_MISMATCH | The subnet region does not match the IPv6 CIDR block region. | | 404 | INVALID\_DHCP\_OPTIONS\_SET\_NOT\_FOUND | The DHCP options set is not found. | | 400 | INVALID\_IP\_BROADCAST\_ADDRESS | The IP address cannot be a broadcast address. | | 400 | INVALID\_MASK\_LENGTH | The IPv6 address mask length must be greater than or equal to the subnet IPv6 prefix length. | | 400 | INVALID\_PARAMETER\_SUBNET\_CIDR\_NOT\_BELONG\_VPC | The subnet does not belong to the specified VPC. | | 400 | INVALID\_PARAMETER\_SUBNET\_IPV6\_TYPE\_NOT\_FOUND | ipv6Type is not found. | | 404 | INVALID\_REGION\_NOT\_FOUND | Specified availability zone does not exist. | | 400 | INVALID\_REGION\_NOT\_ON\_SALE | Subnet is not available for sale in the specified region. | | 400 | INVALID\_SUBNET\_NETMASK\_MAX\_RANGE | Subnet mask length exceeds the maximum value. | | 404 | INVALID\_VPC\_NOT\_FOUND | The global VPC does not exist. | | 400 | OPERATION\_DENIED\_CIDR\_BLOCK\_IS\_EXIST | CIDR block already exists. | | 400 | OPERATION\_DENIED\_NO\_AVAILABLE\_CIDR | No available CIDR block. | | 400 | OPERATION\_DENIED\_REGION\_NOT\_SUPPORT\_PUB\_IPV6 | Public IPv6 is not supported in the specified region. | | 400 | OPERATION\_DENIED\_SUBNET\_CIDR\_CONFLICT | Subnet CIDR ranges conflict. | | 400 | OPERATION\_DENIED\_VPC\_NOT\_SUPPORT\_PRI\_IPV6 | Private IPv6 is not supported for the specified global VPC. | --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.console.zenlayer.com/api-reference/compute/zec/vpc-network/createsubnet.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.