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 the required preparations are made. For more information, see Preparations.

Procedure

  1. Log on to the CLB console.
  2. On the Instances page, click Create CLB.
  3. Set the following parameters to create a CLB instance.
    Parameter Description
    Region

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

    Note Make sure that the CLB instance and the Elastic Compute Service (ECS) instances that you want to specify as backend servers belong to the same region.
    Zone Type Specify whether you want to deploy the CLB instance in one zone or across multiple zones. A zone represents an Alibaba Cloud 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 can still serve your workloads. 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. The primary zone is used to distribute network traffic by default. When the primary zone is down, the system automatically switches to the secondary zone and continues to provide load balancing services. This ensures high service availability.
    Primary Zone Select the primary zone for the CLB instance to distribute network traffic.
    Backup Zone Select the secondary zone for the CLB instance. The secondary zone distributes network traffic only when 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 characters such as letters, digits, hyphens (-), forward slashes (/), periods (.), and underscores (_).

    Instance Spec

    Select a specification for the CLB instance.

    The performance of the CLB instance varies based on the specification. For more information, see 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. Internet is selected in this example.
    • 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.
    • 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 Overview.

    IP Version Select the 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.

    Internet Charge Type 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 CLB instance belongs.
  4. Click Buy Now and complete the payment.