Help Center/ Enterprise Router/ Best Practices/ Using Enterprise Router to Migrate the Network Set Up Through Direct Connect (Global DC Gateway)/ Overview
Updated on 2025-03-28 GMT+08:00
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Overview

Scenario

Before Enterprise Router is launched, you can use Direct Connect to set up a hybrid cloud network. If your on-premises data center needs to access multiple VPCs, you may need more than one Direct Connect connection to improve network reliability, which may result in the following problems:
  • Multiple connections may lead to complex networking and incur higher O&M costs.
  • Connections are independent of each other and cannot work in load balancing or active/standby mode.

To improve the reliability of your hybrid cloud network and reduce O&M costs, you can use an enterprise router to reconstruct the network.

This practice describes how you can use an enterprise router and global DC gateways to migrate a network set up through Direct Connect without interrupting services.

For more information about Enterprise Router, see Enterprise Router Service Overview.

Architecture

Your on-premises data center is connected to the desired VPC (VPC-X) through Direct Connect, and VPC-X, virtual gateway VGW-A, and two virtual interfaces (VIF-A01 and VIF-A02) are in the same region. To improve the reliability of your hybrid cloud network and reduce O&M costs, you can use global DC gateways and Enterprise Router to migrate the network.

This process consists of three phases: before migration, during migration, and after migration. The details are as follows:
  1. Before the migration, virtual gateway VGW-A directly connects to VPC-X and works with virtual interfaces VIF-A01 and VIF-A02 to allow the on-premises data center to access VPC-X.
  2. During migration
    1. Attach VPC-X and virtual gateway VGW-A to an enterprise router. In the route table of VPC-X, ensure that the routes of the virtual gateway and of the enterprise router do not conflict with each other. A CIDR block larger than the on-premises network CIDR block will be used to avoid route conflicts.
    2. Create a global DC gateway DGW-B01.

      DGW-B01 is used to replace VGW-A after the migration.

    3. Delete virtual interface VIF-A01 created for virtual gateway VGW-A, create virtual interface VIF-B01 for global DC gateway DGW-B01, and attach global DC gateway DGW-B01 to the enterprise router.

      Virtual interface VIF-B01 is used to replace virtual interface VIF-A01 after the migration. The on-premises data center can access VPC-X through the enterprise router.

    4. Create global DC gateway DGW-B02.

      DGW-B02 is used to replace VGW-A after the migration.

    5. Delete virtual interface VIF-A02 created for virtual gateway VGW-A, create virtual interface VIF-B02 for global DC gateway DGW-B02, and attach global DC gateway DGW-B02 to the enterprise router.

      VIF-B02 is used to replace VIF-A02 after the migration.

  3. When the on-premises data center can access the VPC through the enterprise router, delete virtual gateway VGW-A.
Figure 1 Architecture diagram

Advantages

As a high-performance central hub on the cloud, an enterprise router can connect multiple network instances. For example, if multiple VPCs and Direct Connect virtual gateways are attached to an enterprise router, the VPCs can share Direct Connect connections to connect to the on-premises data center.
  • Enterprise routers support route learning, which frees you from complex configurations and simplifies O&M.
  • Enterprise routers make it possible for multiple connections to work in load balancing or active/standby mode.

Constraints

Using Enterprise Router to migrate a network set up through Direct Connect may cause intermittent disconnections. Submit a service ticket to evaluate the migration solution.

If a service VPC is being used by ELB, VPC Endpoint, NAT Gateway (private NAT gateway), Distributed Cache Service (DCS), or hybrid DNS, this VPC cannot be attached to an enterprise router.