Last updated: 2021-05-12 10:21:08

1. API Description

Domain name for API request:

This API is used to create a subnet.

  • You must create a VPC instance before creating a subnet.
  • After the subnet is successfully created, its IP address range cannot be modified. The subnet IP address range must fall within the VPC IP address range. They can be the same if the VPC instance has only one subnet. We recommend that you keep the subnet IP address range within the VPC IP address range to reserve IP address ranges for other subnets.
  • The subnet mask of the smallest IP address range that can be created is 28 (16 IP addresses), and that of the largest IP address range is 16 (65,536 IP addresses).
  • IP address ranges of different subnets cannot overlap with each other within the same VPC instance.
  • A subnet is automatically associated with the default route table once created.
  • You can bind a tag when creating a subnet. The tag list in the response indicates the tags that have been successfully added.

A maximum of 100 requests can be initiated per second for this API.

Note: This API supports Finance regions. If the common parameter Region is a Finance region, a domain name with the Finance region needs to be specified, for example:

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2. Input Parameters

The following request parameter list only provides API request parameters and some common parameters. For the complete common parameter list, see Common Request Parameters.

Parameter Name Required Type Description
Action Yes String Common parameter. The value used for this API: CreateSubnet.
Version Yes String Common parameter. The value used for this API: 2017-03-12.
Region Yes String Common parameter. For more information, please see the list of regions supported by the product.
VpcId Yes String The ID of the VPC instance to be operated on. You can obtain the parameter value from the VpcId field in the returned result of DescribeVpcs API.
SubnetName Yes String The subnet name. The maximum length is 60 bytes.
CidrBlock Yes String The subnet IP address range. It must be within the VPC IP address range. Subnet IP address ranges cannot overlap with each other within the same VPC.
Zone Yes String The ID of the availability zone in which the subnet resides. You can set up disaster recovery across availability zones by choosing different availability zones for different subnets.
Tags.N No Array of Tag Bound tags, such as [{"Key": "city", "Value": "shanghai"}].
CdcId No String CDC instance ID

3. Output Parameters

Parameter Name Type Description
Subnet Subnet Subnet object.
RequestId String The unique request ID, which is returned for each request. RequestId is required for locating a problem.

4. Example

Example1 Creating a subnet

Input Example
&<Common request parameters>

Output Example

  "Response": {
    "Subnet": {
      "VpcId": "vpc-m3ul053f",
      "IsDefault": false,
      "SubnetName": "TestSubnet",
      "Zone": "ap-guangzhou-1",
      "SubnetId": "subnet-2qhl25io",
      "CidrBlock": "",
      "TotalIpAddressCount": 253,
      "AvailableIpAddressCount": 253,
      "TagSet": [
          "Key": "city",
          "Value": "shanghai"

5. Developer Resources


TencentCloud API 3.0 integrates SDKs that support various programming languages to make it easier for you to call APIs.

Command Line Interface

6. Error Code

The following only lists the error codes related to the API business logic. For other error codes, see Common Error Codes.

Error Code Description
InvalidParameter A parameter error occurred.
InvalidParameterValue Incorrect parameter value.
InvalidParameterValue.Empty Missing parameters.
InvalidParameterValue.LimitExceeded The parameter value exceeds the limit.
InvalidParameterValue.Malformed Invalid input parameter format.
InvalidParameterValue.SubnetConflict Subnet CIDR conflict.
InvalidParameterValue.SubnetRange Invalid subnet CIDR.
InvalidParameterValue.TooLong Invalid parameter value. The parameter value is too long.
InvalidParameterValue.ZoneConflict The Zone parameter value should be the zone where CDC resides.
LimitExceeded Quota limit is reached.
MissingParameter Missing parameter.
ResourceNotFound The resource does not exist.
UnsupportedOperation.DcGatewaysNotFoundInVpc No direct connect gateway exists in the specified VPC.