A Classic Load Balancer (CLB) instance is an entity that provides load balancing services. To use the Classic Load Balancer (CLB) service, you must first create a CLB instance.

Prerequisites

Before you create a CLB instance, make sure that you have made the required preparations. For more information, see Make preparations.

Procedure

  1. Log on to the CLB console.
  2. On the Instances page, click Create CLB.
  3. Configure the CLB instance based on the following information.
    Parameter Description
    Region

    Select the region where you want to create the CLB instance.

    Note Make sure that the CLB instance and the ECS instances that act as backend servers are deployed in the same region.
    Zone Type Select a zone type for the instance. A zone represents a data center that contains a set of independent infrastructure resources. The infrastructure resources (such as networks, power supply, and air-conditioning) in different zones are independent of each other. Therefore, when the infrastructure resources in one zone are down, the other zones are not affected. Each zone belongs to a specific region. A region may contain one or more zones. Multi-zone Classic Load Balancer (CLB) instances are available in most regions.
    • Single zone: The CLB instance is deployed in only one zone.
    • Multi-zone: The CLB instance is deployed across two zones. By default, the primary zone is used to distribute network traffic. When the primary zone is down, the system automatically switches to the secondary zone and continues to provide load balancing services. This ensures high availability of the service.
    Primary Zone Select a primary zone for the CLB instance. The primary zone distributes traffic in normal conditions.
    Backup Zone Select a secondary zone for the CLB instance. By default, the secondary zone distributes traffic only if the primary zone is down.
    Instance name Enter a name for the CLB instance.

    The name must be 1 to 80 characters in length, and can contain letters, digits, hyphens (-), forward slashes (/), periods (.), and underscores (_).

    LoadBalancerSpec

    Select a specification for the CLB instance.

    The performance metrics of CLB instances vary based on the specifications. For more information, see SLB instance overview.

    Instance Type You can create an Internet-facing CLB instance or an internal-facing CLB instance based on your business requirements. The system allocates a public or private IP address to the CLB instance based on the specified instance type. Public Network is selected in this example.
    • Public Network: If you create an Internet-facing CLB instance, a public IP address is allocated to the CLB instance. In this case, the CLB instance can provide services over the Internet.
    • Internal Network: If you create an internal-facing CLB instance, a private IP address is allocated to the CLB instance. You can access the CLB instance only within the networks of Alibaba Cloud. You cannot access the CLB instance over the Internet.

    For more information, see SLB instance overview.

    IP Version Select the IP protocol that is used by the CLB instance. You can select IPv4 or IPv6.

    For more information about the regions and zones that support IPv6 CLB instances, see Overview of IPv6 CLB instances.

    Billing Method Select a billing method.
    Quantity Specify the number of CLB instances that you want to purchase.
    Resource Group Select the resource group to which the cloud resource belongs.
  4. Click Buy Now and complete the payment.