Use OpenAPI Explorer to create an ALB instance and assign private IP addresses

Usage notes

• You can assign private IPv4 addresses only to IPv4 or dual-stack ALB instances. Private IPv6 addresses are not supported by dual-stack ALB instances.

• For creating an upgraded ALB instance, the vSwitch you specify in each selected zone has enough available IP addresses. An upgraded ALB instance will be allocated with three IP addresses from the vSwitch you specify: One acts as a virtual IP address (VIP) to provide load balancing services, and the other two as local IP addresses to communicate with backend servers. If the vSwitch you specify does not have enough available IP addresses, an error is reported and upgraded ALB instances cannot be created. For more information about upgraded ALB instances, see ALB instance upgrade. (This is not a prerequisite for creating a non-upgraded ALB instance.)

  To ensure upgraded ALB instances auto-scale resources as expected, we recommend that each vSwitch you specify for them has at least eight available IP addresses.

  • Call the DescribeZones operation to query the zones where ALB is available within a specified region.

  • Call the DescribeVSwitches operation to query created vSwitches and their respective CIDR blocks.

Procedure

1. Log on to OpenAPI Explorer.

2. On the CreateLoadBalancer page, set the request parameters. In this example, Region is set to China (Hangzhou).

   The following table describes only the parameters that are relevant to this topic. For more information about how to specify the other parameters, see CreateLoadBalancer.

   Parameter	Description	Example

   Parameter	Description	Example
   VpcId	The ID of the virtual private cloud (VPC) in which the ALB instance resides. To view the VPC ID, log on to the VPC console, select China (Hangzhou) from the top navigation bar, click VPC in the left-side navigation pane, and then find the VPC that you want to view.	vpc-bp1wfo2ytjbr9zs3y****
   AddressType	The network type of the IPv4 address that you want to assign to the ALB instance. Internet: a public IPv4 address. Domain names are resolved to the public IPv4 address, which is accessible over the Internet. Intranet: a private IPv4 address. Domain names are resolved to the private IPv4 address, which is accessible only within the VPC of the ALB instance. Specify Internet or Intranet based on your business requirements.	Intranet
   LoadBalancerName	The name of the ALB instance.	ALB-test01
   ZoneMappings	The mappings between zones and vSwitches. If the region has two or more zones, select at least two zones to ensure service high availability. VSwitchId: the ID of the vSwitch in the zone. You can call the DescribeVSwitches operation to query the vSwitch IDs. ZoneId: the ID of the zone. You can call the DescribeZones operation to query zone IDs. IntranetAddress: the IPv4 address that you want to assign to the ALB instance. Important When you assign the private IP address to the ALB instance, make sure that the address belongs to the destination CIDR block of the vSwitch and is not in use. To view vSwitch IDs and CIDR blocks, log on to the VPC console, select China (Hangzhou) from the top navigation bar, click VPC in the left-side navigation pane, and then find the VPC of the ALB instance. On the Resource Management tab, click the number below the vSwitch parameter. Then, you can view the vSwitch IDs and CIDR blocks.	In this example, Zone G and Zone I are specified. Specify zones based on the region of your ALB instance. Zone G settings: ZoneMappings.1.VSwitchI: vsw-bp1jiciza3mpuyphn**** ZoneMappings.1.ZoneId: cn-hangzhou-g ZoneMappings.1.IntranetAddress: 192.168.1.13 Zone I settings: ZoneMappings.0.VSwitchId: vsw-bp1uwoih7uwew975k**** ZoneMappings.0.ZoneId: cn-hangzhou-i ZoneMappings.0.IntranetAddress: 192.168.0.230
   LoadBalancerEdition	The edition of the ALB instance. The features and billing rules vary based on the edition of the ALB instance. Valid values: Basic Standard StandardWithWaf	Basic
   AddressAllocatedMode	The mode in which IP addresses are allocated. Valid values: Fixed (default): assigns a static IP address to the ALB instance for each zone. Dynamic: IP addresses are dynamically assigned to an ALB instance for each zone. Note Starting at 00:00:00 on February 25, 2025 (UTC+8), ALB instances that you create using the CreateLoadBalancer operation are all the upgraded version, regardless of the IP mode you specify in the request. ALB instances do not differentiate between static and fixed modes and can auto-scale resources as load fluctuates. Non-upgraded ALB instances are not affected.	Fixed
   LoadBalancerBillingConfig	The configuration of the billing method of the ALB instance. PayType: the billing method of the ALB instance. Set the value to PostPay, which specifies the pay-as-you-go billing method. BandwidthPackageId: the ID of the Internet Shared Bandwidth instance if the ALB instance is Internet-facing.	PayType: PostPay is specified in this example. BandwidthPackageId: Set this parameter based on your business requirements.
   AddressIpVersion	The protocol version. Valid values: IPv4 (default) DualStack IPv4 and DualStack are supported. Specify an IP version based on your business requirements. If you specify DualStack, make sure that the vSwitch of the ALB instance has IPv6 enabled. For more information, see Enable IPv6 for a vSwitch.	IPv4

3. Click Initiate Call.

   The following result is returned. If the returned HTTP status code is 200, the NLB instance is created. If other HTTP status codes are returned, troubleshoot the error based on the error message. For more information, see ALB status codes.

   {
     "RequestId": "0A1F39B6-4BDE-5923-A3BE-E98708413D1B",
     "LoadBalancerId": "alb-gokux4i116yiqf****"
   }

   After the request is sent, you can call the GetLoadBalancerAttribute operation to query the configurations of the ALB instance. In the response, IntranetAddress indicates the private IP address you specified.

4. Optional. After the ALB instance is created, you can log on to the ALB console to check whether the private IP addresses of the ALB instance are 192.168.1.13 and 192.168.0.230.

   1. In the top navigation bar, select the China (Hangzhou) region.

   2. On the Instances page, click the ID of the ALB instance that you want to manage.

   3. On the Instance Details tab, VIP indicates the private IP address you specified.

References

• For more information about how to create an ALB instance in the console, see Create an ALB instance.

• For more information about how to assign a private IP address to an NLB instance, see Specify private IP addresses when you create an NLB instance by using OpenAPI Explorer.

• For more information about how to assign a private IP address to a Classic Load Balancer (CLB) instance, see Specify a private IP address when you use OpenAPI Explorer to create a CLB instance in a VPC.