After you connect your data center to an access point of Alibaba Cloud through an Express Connect circuit, you must attach the associated virtual border router (VBR) to a Cloud Enterprise Network (CEN) instance. The CEN instance must be connected to the virtual private cloud (VPC) that you want to access. This way, your data center can communicate with the VPC through private connections.


  • Your data center is connected to Alibaba Cloud through an Express Connect circuit. In addition, a VBR is created for the Express Connect circuit. For more information, see Create a VBR.
  • A CEN instance is created and the VPC that you want to access is attached to the CEN instance. For more information, see Create a CEN instance.

Background information

CEN helps you build a global network for hybrid cloud environments or distributed systems. CEN supports automatic route distribution and learning, which accelerates network convergence and improves the quality and security of cross-region communications.

Network instances such as VPCs, VBRs, and Cloud Connect Network (CCN) instances that are created in the same region and attached to the same CEN instance can communicate with each other through private connections free of charge. Data transfer between network instances in different regions is charged. For example, if you want a VBR in the China (Hangzhou) region and a VPC in the US (Silicon Valley) to communicate with each other, you must purchase a bandwidth plan and allocate bandwidth to the cross-region connection. For more information, see Allocate bandwidth for cross-region communication.

Connect to a VPC


  1. Log on to the Express Connect console.
  2. In the top navigation bar, select the region and click Virtual Border Routers (VBRs) in the left-side navigation pane.
  3. On the Virtual Border Routers (VBRs) page, find the VBR that you want to manage and click its ID.
  4. In the Basic Information section, click Join CEN.
  5. In the Join CEN panel, select the CEN instance to which you want to attach the VBR and click OK.