This topic describes how to migrate virtual private clouds (VPCs) and virtual border routers (VBRs) that use Express Connect peering connections to a Cloud Enterprise Network (CEN) instance. You can use CEN to establish private connections between VPCs, and between VPCs and data centers. CEN supports automatic route distribution and learning, which speeds up network convergence, improves the quality and security of cross-network communications, and connects all network resources.
After a CEN instance is created, you can attach VPCs and VBRs that use peering connections to the CEN instance, and then configure routes.
The CEN instance automatically learns and distributes the routes of the attached network instances. After a VPC or VBR that uses a peering connection is attached to a CEN instance, the static route of the peering connection has a higher priority than the dynamic route of the CEN instance. If a route from the CEN instance is more specific than or has the same destination as the static route of the peering connection, the route cannot be learned. To ensure a successful migration, we recommend that you split a route that points to a large CIDR block into multiple child routes. After the CEN instance learns the child routes, you can delete the child routes. For more information about how to migrate VPCs and VBRs to a CEN instance, see Migrate a VBR from a peering connection to a CEN instance and Migrate a VPC from a peering connection to a CEN instance.
Differences between connections of CEN and peering connections of Express Connect
You can use CEN to establish private connections between VPCs, and between VPCs and data centers. CEN is developed with more flexible and simplified configurations than peering connections of Express Connect. In addition, connections that are established through CEN are more stable. The following table describes the differences in detail.
|Network connection||Network-wide interconnection
All networks (VPCs and Virtual Border Routers) associated with a CEN instance are interconnected with each other. A secure, reliable, and high-speed intranet communication channel can be established between any two networks.
|Single point interconnection
Express Connect connections cannot be extended. Specifically, the VPCs or on-premises data centers that are connected through Express Connect can only communicate with the peer VPCs.
|Route management||Dynamic learning
Based on the Fullmesh link, CEN dynamically learns and distributes routes, which improves the convergence of routes, and the quality and security of network communication.
Express Connect requires end-to-end manual route configuration.
|Bandwidth management||Cross-region shared bandwidth package
CEN provides bandwidth packages which are sold by region to facilitate cross-region bandwidth adjustments. Bandwidth packages also help optimize resource allocation and save costs.
The bandwidth of an Express Connect connection must be specified when you create the connection. You can adjust the bandwidth value after you create an Express Connect connection, but you cannot change the connected regions.