Help Center/ Enterprise Router/ User Guide (Kuala Lumpur Region)/ Getting Started/ Selecting a Networking Scheme
Updated on 2025-12-15 GMT+08:00
View PDF
Share

Selecting a Networking Scheme

You can use enterprise routers to build a central network to simplify the network architecture. The following uses connectivity between service VPCs as an example and provides two typical networking schemes, as shown in the following figures. Table 1 describes the two schemes in detail.
Figure 1 Networking for allowing an on-premises data center to access two service VPCs directly (scheme 1)
Figure 2 Networking for allowing an on-premises data center to access two service VPCs over a transit VPC (scheme 2)
Table 1 Comparison between the two schemes

Scheme

Networking Architecture

Network Path Description

Remarks

Scheme 1

Figure 1

All service VPCs (VPC-A, VPC-B, and VPC-C) are attached to an enterprise router.

VPC-A, VPC-B, and VPC-C are connected through the enterprise router.

For details, see How Do I Select a Networking Scheme?

Scheme 2

Figure 2

The two service VPCs (VPC-A and VPC-B) are not attached to the enterprise router. Instead, a transit VPC (VPC-Transit) is used. The transit VPC and VPC-C are attached to the enterprise router.
  • Each service VPC (VPC-A and VPC-B) is connected to the transit VPC over a VPC peering connection.
  • VPC-A, VPC-B, and VPC-C are connected through the transit VPC and enterprise router.

How Do I Select a Networking Scheme?

In scheme 1, the service VPCs are directly attached to the enterprise router. In scheme 2, a transit VPC is used and attached to the enterprise router. Each service VPC is connected to the transit VPC over a VPC peering connection. Compared with scheme 1, scheme 2 costs less and eliminates some constraints, as detailed below:
  • Scheme 2 frees you from the following constraints that scheme 1 has on attaching service VPCs to an enterprise router:
    • If a service VPC is used by a shared load balancer, VPC endpoint, private NAT gateway, or DCS resource, contact customer service to confirm the service compatibility and preferentially use a transit VPC for networking.
    • Traffic cannot be forwarded from a VPC to its attached enterprise router if the destination of a route with an enterprise router as the next hop is set to 0.0.0.0/0 in the VPC route table and if:
      • An ECS in the VPC has an EIP bound.
      • The VPC is being used by ELB (either dedicated or shared load balancers), NAT Gateway, VPC Endpoint, or DCS.

If you still want to use scheme 1 to attach service VPCs to an enterprise router, contact customer service to evaluate the feasibility.

Parent topic: Getting Started