# Updating Subnet Information

#### Function

This API is used to update information about a subnet.

#### URI

PUT /v1/{project_id}/vpcs/{vpc_id}/subnets/{subnet_id}

Table 1 describes the parameters.

Table 1 Parameter description
Name | Mandatory | Description
--- | --- | ---
project_id | Yes | Specifies the project ID.
vpc_id | Yes | Specifies the VPC ID of the subnet.
subnet_id | Yes | Specifies the subnet ID, which uniquely identifies the subnet. If you use the management console, the value of this parameter is the Network ID value.

#### Request Message

- Request parameter

  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 >).

  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 system automatically sets it 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. Exercise caution when performing this operation.

  primary_dns

  No

  String

  - Specifies the IP address of DNS server 1 on the subnet.
  - The value must be a valid IP address.

  secondary_dns

  No

  String

  - Specifies the IP address of DNS server 2 on the subnet.
  - The value must be a valid IP address.

  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.

  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.

  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

      PUT https://{Endpoint}/v1/{project_id}/vpcs/{vpc_id}/subnets/4779ab1c-7c1a-44b1-a02e-93dfc361b32d

      {
          "subnet": {
              "name": "subnetqq",
              "ipv6_enable": true,
              "dhcp_enable": false,
              "primary_dns": "114.xx.xx.115",
              "secondary_dns": "114.xx.xx.116",
              "extra_dhcp_opts": [
                  {
                      "opt_value": "10.100.0.33,10.100.0.34",
                      "opt_name": "ntp"
                  }
              ]
          }
      }

#### Response Message

- Response parameter

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

  Table 6 subnet objects
  Name | Type | Description
  --- | --- | ---
  id | String | Specifies a resource ID in UUID format.

  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.

- Example response

      {
          "subnet": {
              "id": "4779ab1c-7c1a-44b1-a02e-93dfc361b32d",
              "status": "ACTIVE"
          }
      }

#### Status Code

See Status Codes.

#### Error Code

See Error Codes.

Parent topic: Subnet