This topic describes how to migrate virtual private clouds (VPCs) and virtual border routers (VBRs) that use Express Connect peer 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 uses automatic route learning and distribution to accelerate network convergence and improve the quality of cross-network communication. This way, all network instances attached to CEN can communicate with each other.
After you prepare a CEN instance, you can attach VPCs and VBRs that use peer 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 peer connection is attached to a CEN instance, the static route of the peer 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 the same as the static route of the peer connection, the route cannot be learnt. 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 them. For more information about how to migrate VPCs and VBRs to a CEN instance, see Migrate a VPC from a peering connection to a CEN instance and Migrate a VBR from a peering connection to a CEN instance.
Differences between connections of CEN and peer connections of Express Connect
You can establish private connections between VPCs that are attached to a CEN instance, and between VPCs and data centers. CEN is developed with more flexible and simplified configurations than peer 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.