Creating a Subnet

Function

This API is used to create a subnet.

Notes and Constraints

IPv6 subnets can be created only when IPv4 subnets have been created on the network.
A VXLAN network can have only one IPv4 subnet and one IPv6 subnet.

URI

POST /v1/{project_id}/subnets

Table 1 describes the parameters.

**Table 1** Parameter description
Name	Mandatory	Description
project_id	Yes	Specifies the project ID. For details about how to obtain a project ID, see Obtaining a Project ID.

Request Parameters

**Table 2** Request parameter
Name	Mandatory	Type	Description
subnet	Yes	subnet object	Specifies the subnet objects.

**Table 3** **subnet** objects
Name	Mandatory	Type	Description
name	Yes	String	Specifies the subnet name. The value can contain 1 to 64 characters, including letters, digits, underscores (_), hyphens (-), and periods (.).
description	No	String	Provides supplementary information about the subnet. The value can contain no more than 255 characters and cannot contain angle brackets (< or >).
cidr	Yes	String	Specifies the subnet CIDR block. The value must be within the VPC CIDR block. The value must be in CIDR format. The subnet mask cannot be greater than 28.
gateway_ip	Yes	String	Specifies the gateway of the subnet. The value must be an IP address in the subnet. The value must be a valid IP address.
ipv6_enable	No	Boolean	Specifies whether IPv6 is enabled. If IPv6 is enabled, you can use IPv6 CIDR blocks. The value can be true (enabled) or false (disabled). If this parameter is left blank, the system automatically sets it to false by default.
dhcp_enable	No	Boolean	Specifies whether DHCP is enabled for the subnet. The value can be true (enabled) or false (disabled). If this parameter is left blank, the value is set to true by default. If this parameter is set to false, newly created ECSs cannot obtain IP addresses, and usernames and passwords cannot be injected using Cloud-init.
primary_dns	No	String	Specifies the IP address of DNS server 1 on the subnet. The value must be an IP address. IPv6 addresses are not supported. If the value is not specified, the default value will be left blank.
secondary_dns	No	String	Specifies the IP address of DNS server 2 on the subnet. The value must be an IP address. IPv6 addresses are not supported. If the value is not specified, the default value will be left blank. If only secondary_dns is specified and primary_dns is not specified, primary_dns will automatically use the value of secondary_dns. If there is only one DNS server address, only primary_dns is displayed.
dnsList	No	Array of strings	Specifies the DNS server address list of a subnet. This field is required if you need to use more than two DNS servers. This parameter value is the superset of both DNS server address 1 and DNS server address 2. If the value is not specified, the default value will be left blank.
availability_zone	No	String	Specifies the AZ to which the subnet belongs, which can be obtained from endpoints. For details, see Endpoints. The value must be an existing AZ in the system. If the value is not specified, the default value will be left blank.
vpc_id	Yes	String	Specifies the ID of the VPC to which the subnet belongs.
extra_dhcp_opts	No	Array of extra_dhcp_opt objects	Specifies the NTP server address configured for the subnet. For details, see Table 4.

**Table 4** **extra_dhcp_opt** object
Name	Mandatory	Type	Description
opt_value	No	String	Specifies the NTP server address configured for the subnet. Constraints: The option ntp for opt_name indicates the NTP server configured for the subnet. Currently, only IPv4 addresses are supported. A maximum of four IP addresses can be configured, and each address must be unique. Multiple IP addresses must be separated using commas (,). The option null for opt_name indicates that no NTP server is configured for the subnet. The parameter value cannot be an empty string. The option ipv6_addresstime for opt_name indicates the DHCP lease expiration time of the IPv6 subnet. The value can be -1, which indicates unlimited lease time, or Number+h. The number ranges from 1 to 175,200. For example, the value can be 5h. The default value is 2h.
opt_name	Yes	String	Specifies the NTP server address name configured for the subnet. Currently, the value can only be set to ntp.

Example Request

Create a subnet with name set to subnet, CIDR block set to 192.168.20.0/24, and gateway IP address set to 192.168.20.1 in the VPC with ID of 3ec3b33f-ac1c-4630-ad1c-7dba1ed79d85.

POST https://{Endpoint}/v1/{project_id}/subnets

{
    "subnet": {
        "name": "subnet",
        "description": "",
        "cidr": "192.168.20.0/24",
        "gateway_ip": "192.168.20.1",
        "ipv6_enable": true,
        "dhcp_enable": true,
        "primary_dns": "114.xx.xx.114",
        "secondary_dns": "114.xx.xx.115",
        "dnsList": [
            "114.xx.xx.114",
            "114.xx.xx.115"
        ],
        "availability_zone": "aa-bb-cc",
        "vpc_id": "3ec3b33f-ac1c-4630-ad1c-7dba1ed79d85"
    }
}

Response Parameters

**Table 5** Response parameter
Name	Type	Description
subnet	subnet object	Specifies the subnet objects.

**Table 6** **subnet** objects
Name	Type	Description
id	String	Specifies the resource identifier in the form of UUID.
name	String	Specifies the subnet name. The value can contain 1 to 64 characters, including letters, digits, underscores (_), hyphens (-), and periods (.).
description	String	Provides supplementary information about the subnet. The value can contain no more than 255 characters and cannot contain angle brackets (< or >).
cidr	String	Specifies the subnet CIDR block. The value must be within the VPC CIDR block. The value must be in CIDR format. The subnet mask cannot be greater than 28.
gateway_ip	String	Specifies the gateway of the subnet. The value must be an IP address in the subnet. The value must be a valid IP address.
ipv6_enable	Boolean	Specifies whether an IPv6 subnet can be created.
cidr_v6	String	Specifies the IPv6 subnet CIDR block. If the subnet is an IPv4 subnet, this parameter is not returned.
gateway_ip_v6	String	Specifies the IPv6 subnet gateway. If the subnet is an IPv4 subnet, this parameter is not returned.
dhcp_enable	Boolean	Specifies whether DHCP is enabled for the subnet.
primary_dns	String	Specifies the IP address of DNS server 1 on the subnet. The value must be an IP address. IPv6 addresses are not supported. If the value is not specified, the default value will be left blank.
secondary_dns	String	Specifies the IP address of DNS server 2 on the subnet. The value must be an IP address. IPv6 addresses are not supported. If the value is not specified, the default value will be left blank. If only secondary_dns is specified and primary_dns is not specified, primary_dns will automatically use the value of secondary_dns. If there is only one DNS server address, only primary_dns is displayed.
dnsList	Array of strings	Specifies the DNS server address list of a subnet. This field is required if you need to use more than two DNS servers. This parameter value is the superset of both DNS server address 1 and DNS server address 2. If the value is not specified, the default value will be left blank.
availability_zone	String	Specifies the AZ to which the subnet belongs, which can be obtained from endpoints. For details, see Endpoints. The value must be an existing AZ in the system. If the value is not specified, the default value will be left blank.
vpc_id	String	Specifies the ID of the VPC to which the subnet belongs.
status	String	Specifies the status of the subnet. The value can be ACTIVE, UNKNOWN, or ERROR. ACTIVE: indicates that the subnet has been associated with a VPC. UNKNOWN: indicates that the subnet has not been associated with a VPC. ERROR: indicates that the subnet is abnormal. The system creates a subnet and then associates the subnet with a VPC in the threads. In the concurrent scenario, if the CIDR block of the created subnet is the same as that of an existing subnet, the created subnet fails to associate with a VPC after underlying system verification. As a result, the subnet creation fails. In this scenario, the returned value of status is UNKNOWN.
neutron_network_id	String	Specifies the ID of the corresponding network (OpenStack Neutron API).
neutron_subnet_id	String	Specifies the ID of the corresponding subnet (OpenStack Neutron API).
neutron_subnet_id_v6	String	Specifies the ID of the IPv6 subnet (OpenStack Neutron API). If the subnet is an IPv4 subnet, this parameter is not returned.
extra_dhcp_opts	Array of extra_dhcp_opt objects	Specifies the NTP server address configured for the subnet. For details, see Table 7.

**Table 7** **extra_dhcp_opt** object
Name	Mandatory	Type	Description
opt_value	No	String	Specifies the NTP server address configured for the subnet. Constraints: The option ntp for opt_name indicates the NTP server configured for the subnet. Currently, only IPv4 addresses are supported. A maximum of four IP addresses can be configured, and each address must be unique. Multiple IP addresses must be separated using commas (,). The option null for opt_name indicates that no NTP server is configured for the subnet. The parameter value cannot be an empty string. The option ipv6_addresstime for opt_name indicates the DHCP lease expiration time of the IPv6 subnet. The value can be -1, which indicates unlimited lease time, or Number+h. The number ranges from 1 to 175,200. For example, the value can be 5h. The default value is 2h.
opt_name	Yes	String	Specifies the NTP server address name configured for the subnet. Currently, the value can only be set to ntp.

Example Response

{
    "subnet": {
        "id": "4779ab1c-7c1a-44b1-a02e-93dfc361b32d",
        "name": "subnet",
        "description": "",
        "cidr": "192.168.20.0/24",
        "dnsList": [
            "114.xx.xx.114",
            "114.xx.xx.115"
        ],
        "status": "UNKNOWN",
        "vpc_id": "3ec3b33f-ac1c-4630-ad1c-7dba1ed79d85",
        "gateway_ip": "192.168.20.1",
        "ipv6_enable": true, 
        "cidr_v6": "2001:db8:a583::/64",
        "gateway_ip_v6": "2001:db8:a583::1",
        "dhcp_enable": true,
        "primary_dns": "114.xx.xx.114",
        "secondary_dns": "114.xx.xx.115",
        "availability_zone": "aa-bb-cc",
        "neutron_network_id": "4779ab1c-7c1a-44b1-a02e-93dfc361b32d",
        "neutron_subnet_id": "213cb9d-3122-2ac1-1a29-91ffc1231a12",
        "neutron_subnet_id_v6": "e0fa7de1-a6e2-44c9-b052-b9d8cebe93c4",  
    }
}