Updated on 2024-12-09 GMT+08:00

Overview

Scenario

Before enterprise routers are available, VPC peering connections are used to connect VPCs in the same region. VPC peering connections are suitable for simple networks because every two VPCs need a VPC peering connection. In a complex network, a large number of VPC peering connections are required, which is inconvenient for network expansion and increases O&M costs.

As a high-performance centralized router on the cloud, an enterprise router can connect multiple VPCs in the same region, making network expansion and O&M easier.

If you have a lot of VPCs that are connected by VPC peering connections, you can use an enterprise router to replace the VPC peering connections.

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

Architecture

There are three VPCs (VPC-A, VPC-B, and VPC-C) in region A and connected over VPC peering connections. To improve network scalability and reduce O&M costs, you can use an enterprise router to connect the three VPCs.

This process consists of three phases: before migration, during migration, and after migration. The details are as follows:
  1. Before migration: VPC-A, VPC-B, and VPC-C are connected over VPC peering connections.
  2. During migration: VPC-A, VPC-B, and VPC-C will be connected through both VPC peering connections and an enterprise router. Large and small CIDR blocks are used to ensure that the routes of VPC peering connections and the enterprise router do not conflict.
  3. After migration: VPC-A, VPC-B, and VPC-C can communicate with each other through the enterprise router. You can delete all VPC peering connections.
Figure 1 Migrating a network set up through VPC peering connections

Advantages

Enterprise Router simplifies the networking structure, improves the network scalability, and reduces O&M costs.

As shown in Figure 2, the network set up through VPC peering connections is more complex than that set up using an enterprise router. For example, if you have six VPCs, you need to create 15 VPC peering connections. However, you only need one enterprise router to connect all your VPCs. The networking is simple and clear, making O&M and network expansion easier.

Figure 2 Network that you set up through VPC peering connections vs. Network that you set up using an enterprise router

Notes and Constraints

  • If the VPCs connected by VPC peering connections are from different accounts, you can use the sharing function of the enterprise router to connect the VPCs of different accounts through one enterprise router.
  • Using Enterprise Router to migrate a network set up through VPC Peering may interrupt services. 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.

For details about constraints on enterprise routers, see Notes and Constraints.