Virtual Private Cloud (VPC) provides the ClassicLink feature. This feature allows classic network-connected Elastic Compute Service (ECS) instances to communicate with cloud resources deployed in VPCs. Before you establish a ClassicLink connection, you must enable the ClassicLink feature.

Background information

The ClassicLink feature allows classic network-connected ECS instances to communicate with cloud resources such as ECS instances, ApsaraDB RDS instances, and Server Load Balancer (SLB) instances that are deployed in VPCs. VPC-connected ECS instances can access only ECS instances in a classic network that is already connected to the VPC. VPC-connected ECS instances cannot access other cloud resources in the classic network or ECS instances deployed outside the classic network. For more information, see Overview.
Note The ClassicLink feature is supported only in regions that support classic networks. For more information, see View and increase instance quotas.


  1. Log on to the VPC console.
  2. In the top navigation bar, select the region where the VPC is deployed.
  3. On the VPCs page, find the VPC that you want to manage and click its ID.
  4. In the upper-right corner of the VPC details page, click Enable ClassicLink.
  5. In the Enable ClassicLink dialog box, click OK.
    After ClassicLink is enabled, the status of ClassicLink in the VPC Details section changes to Enabled. Enable ClassicLink