# Querying Subnets

#### Function

This API is used to query all subnets accessible to the tenant submitting the request.

#### URI

GET /v2.0/subnets

Example:

    GET https://{Endpoint}/v2.0/subnets?name={subnet_name}&ip_version={ip_version}&network_id={network_id}&cidr={subnet_cidr_address}&gateway_ip={subnet_gateway}&tenant_id={tenant_id}&enable_dhcp={is_enable_dhcp}

Example of querying networks by page

    GET https://{Endpoint}/v2.0/subnets?limit=2&marker=011fc878-5521-4654-a1ad-f5b0b5820302&page_reverse=False

Table 1 describes the parameters.

Table 1 Parameter description
Name | Mandatory | Type | Description
--- | --- | --- | ---
id | No | String | Specifies that the ID is used as the filtering condition.
name | No | String | Specifies that the subnet name is used as the filtering condition.
enable_dhcp | No | Boolean | Specifies whether DHCP is enabled for the subnet is used as the filtering condition. The value can be true or false.
cidr | No | String | Specifies that the CIDR block is used as the filtering condition.
network_id | No | String | Specifies that the network ID is used as the filtering condition.
ip_version | No | String | Specifies that the IP address version is used as the filtering condition.
gateway_ip | No | String | Specifies that the gateway IP address is used as the filtering condition.
tenant_id | No | String | Specifies that the project ID is used as the filtering condition.

marker

No

String

Specifies a resource ID for pagination query, indicating that the query starts from the next record of the specified resource ID.

This parameter can work together with the parameter limit.

- If parameters marker and limit are not passed, all resource records will be returned.
- If the parameter marker is not passed and the value of parameter limit is set to 10, the first 10 resource records will be returned.
- If the value of the parameter marker is set to the resource ID of the 10th record and the value of parameter limit is set to 10, the 11th to 20th resource records will be returned.
- If the value of the parameter marker is set to the resource ID of the 10th record and the parameter limit is not passed, resource records starting from the 11th records (including 11th) will be returned.

limit | No | Integer | Specifies the number of records that will be returned on each page. The value is from 0 to intmax. limit can be used together with marker. For details, see the parameter description of marker.

#### Request Message

None

#### Response Message

Table 2 Response parameter
Parameter | Type | Description
--- | --- | ---
subnets | Array of subnet objects | Specifies the subnet list. For details, see Table 3.
subnets_links | Array of subnets_link objects | Specifies the pagination information. For details, see Table 6. The value of rel will be next and that of href will be a link only when limit is used for filtering and the number of resources exceeds the value of limit or 2000 (default value of limit).

Table 3 subnet objects
Attribute | Type | Description
--- | --- | ---
id | String | Specifies the subnet ID. This parameter is not mandatory when you query subnets.
name | String | Specifies the subnet name.
ip_version | Integer | Specifies the IP address version. Supported versions: IPv4
network_id | String | Specifies the ID of the network to which the subnet belongs.
cidr | String | Specifies the CIDR format. Only the IPv4 addresses in the 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 network segments are supported. In addition, the IPv4 mask cannot be greater than 28.
gateway_ip | String | The gateway IP address cannot conflict with IP addresses configured for allocation_pools. This attribute cannot be modified.

allocation_pools

Array of allocation_pool objects

Specifies available IP address pools. For details, see Table 4.

Example: [ { "start": "10.0.0.2", "end": "10.0.0.251"} ]

The last three and the first IP addresses in each subnet are the ones reserved by the system. For example, in IPv4 subnet 192.168.1.0/24, IP addresses 192.168.1.0, 192.168.1.253, 192.168.1.254, and 192.168.1.255 are reserved by the system.

By default, the IP addresses reserved by the system are not in the IP address pool specified by allocation_pool.

When updating an IP address pool, the allocation_pool value can contain neither gateway nor broadcast IP addresses.

dns_nameservers | Array of strings | Specifies the DNS server address. Example: "dns_nameservers": ["8.xx.xx.8","8.xx.xx.4"]
host_routes | Array of host_route objects | Specifies the static VM routes. For details, see Table 5. Static routes are not supported, and entered information will be ignored.
tenant_id | String | Specifies the project ID.
enable_dhcp | Boolean | Specifies whether to enable the DHCP function. Value false indicates that the DHCP function is not enabled. The value can only be true.
project_id | String | Specifies the project ID.
created_at | String | Specifies the time (UTC) when the subnet is created. Format: yyyy-MM-ddTHH:mm:ss
updated_at | String | Specifies the time (UTC) when the subnet is updated. Format: yyyy-MM-ddTHH:mm:ss

Table 4 allocation_pool objects
Parameter | Type | Description
--- | --- | ---
start | String | Specifies the start IP address of a network pool.
end | String | Specifies the end IP address of a network pool.

Table 5 host_route objects
Parameter | Type | Description
--- | --- | ---
destination | String | Specifies the destination subnet of a route.
nexthop | String | Specifies the next-hop IP address of a route.

Table 6 subnets_link object
Parameter | Type | Description
--- | --- | ---
href | String | Specifies the API link.
rel | String | Specifies the relationship between the API link and the API version.

#### Example

Example request 1

    GET https://{Endpoint}/v2.0/subnets?limit=1

Example response 1

    {
        "subnets": [
            {
                "name": "kesmdemeet",
                "cidr": "172.16.236.0/24",
                "id": "011fc878-5521-4654-a1ad-f5b0b5820302",
                "enable_dhcp": true,
                "network_id": "48efad0c-079d-4cc8-ace0-dce35d584124",
                "tenant_id": "bbfe8c41dd034a07bebd592bf03b4b0c",
                "project_id": "bbfe8c41dd034a07bebd592bf03b4b0c",
                "dns_nameservers": [],
                "allocation_pools": [
                    {
                        "start": "172.16.236.2",
                        "end": "172.16.236.251"
                    }
                ],
                "host_routes": [],
                "ip_version": 4,
                "gateway_ip": "172.16.236.1",
                "created_at": "2018-03-26T08:23:43",
                "updated_at": "2018-03-26T08:23:44"
            }
        ],
        "subnets_links": [
           {
                "rel": "next",
                "href": "https://{Endpoint}/v2.0/subnets?limit=1&marker=011fc878-5521-4654-a1ad-f5b0b5820302"
            },
           {    "rel": "previous",
                "href": "https://{Endpoint}/v2.0/subnets?limit=1&marker=011fc878-5521-4654-a1ad-f5b0b5820302&page_reverse=True"
            }
        ]
    }

Example request 2

    GET https://{Endpoint}/v2.0/subnets?id=011fc878-5521-4654-a1ad-f5b0b5820322

Example response 2

    {
        "subnets": [
            {
    	    "id": "011fc878-5521-4654-a1ad-f5b0b5820322",
    	    "name": "elb_alpha_vpc0_subnet0_172_16_0_0_24",
    	    "tenant_id": "0c55e5b2b100d5202ff6c01a2fac4580",
    	    "network_id": "3053b502-11b2-4599-bcf4-d9d06b6118b2",
                "ip_version": 6,
    	    "cidr": "2001:db8:a583:a0::/64",
                "subnetpool_id": "cb03d100-8687-4c0a-9441-ea568dcae47d",
    	    "allocation_pools": [{
    	        "start": "2001:db8:a583:a0::2",
    		"end": "2001:db8:a583:a0:ffff:ffff:ffff:fffc"
    	    }],
    	    "gateway_ip": "2001:db8:a583:a0::1",
    	    "enable_dhcp": true,
    	    "ipv6_ra_mode": "dhcpv6-stateful",
    	    "ipv6_address_mode": "dhcpv6-stateful",
    	    "description": "",
    	    "dns_nameservers": [],
    	    "host_routes": [],
    	    "project_id": "0c55e5b2b100d5202ff6c01a2fac4580",
    	    "created_at": "2021-07-01T07:59:28",
    	    "updated_at": "2021-07-01T07:59:28"
            }
        ],
        "subnets_links": [
           {    "rel": "previous",
                "href": "https://{Endpoint}/v2.0/subnets?limit=1&id=011fc878-5521-4654-a1ad-f5b0b5820322&marker=011fc878-5521-4654-a1ad-f5b0b5820302&page_reverse=True"
            }
        ]
    }

#### Status Code

See Status Codes.

#### Error Code

See Error Codes.

Parent topic: Subnet