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Cloud Enterprise Network:Connect a VBR to a transit router

Last Updated:Feb 03, 2026

This topic describes how to connect a virtual border router (VBR) to a transit router so that your data center can communicate with virtual private clouds (VPCs) in the same region or across regions, and with other data centers.

Prerequisites

Before you connect a VBR to a transit router, ensure that you have:

Connect a VBR to an Enterprise Edition transit router

  1. Log on to the CEN console.

  2. On the Instances page, click the ID of the CEN instance that you want to manage.

  3. On the Basic Information > Transit Router tab, find the transit router and click Create Connection in the Actions column.

  4. On the Connection with Peer Network Instance page, set the following parameters and click OK.

Parameter

Description

Instance Type

Select Virtual Border Router (VBR).

Region

Select the region where the network instance is deployed.

Transit Router

The transit router in the selected region is displayed.

Resource Owner ID

Current Account if same account; Different Account and enter the primary account ID of the network instance if not.

Attachment Name

A name for the VBR connection.

Tag

Optional. See Tags.

Network Instance

The VBR to connect to the transit router.

Advanced Settings

Optional. Default: Associate with Default Route Table of Transit Router; Propagate System Routes to Default Route Table of Transit Router; Propagate Routes to VBR. See Manage routes.

You can view the VBR connection on the Intra-region Connections tab on the transit router details page. See View network instance connections.

Note

If you see DEVICE_MODEL_FORBIDDEN, see FAQ.

After you create a VBR connection, you can change which transit router route table is associated with it.

Warning

If route synchronization is enabled for the VBR connection, changing the route table withdraws the routes synchronized to the VBR. The routes in the new route table are then synchronized to all route tables of the VBR. See Route synchronization.

  1. Log on to the CEN console.

  2. On the Instances page, click the ID of the CEN instance that you want to manage.

  3. On the Basic Information > Transit Router tab, click the ID of the transit router that you want to manage.

  4. On the Intra-region Connections tab, click the ID of the VBR connection that you want to manage.

  5. In the Attachment Details panel, under Basic Information, click Modify next to Associated Route Table.

  6. In the Modify Route Table dialog box, select a route table and click OK.

Connect a VBR to a Basic Edition transit router

  1. Log on to the CEN console.

  2. On the Instances page, click the ID of the CEN instance that you want to manage.

  3. On the Basic Information > Transit Router tab, find the transit router and click Create Connection in the Actions column.

  4. On the Connection with Peer Network Instance page, set the parameters and click OK.

Parameter

Description

Instance Type

Select Virtual Border Router (VBR).

Region

Select the region where the network instance is deployed.

Transit Router

The transit router in the selected region is displayed. If none exists, the system creates one.

Resource Owner ID

Current Account or Different Account (and enter the network instance primary account ID).

Network Instance

The network instance (VBR) to connect.

View the VBR connection on the Intra-region Connections tab. See View network instance connections.

Note

If you see DEVICE_MODEL_FORBIDDEN, see FAQ.

Connect a VBR by calling API operations

You can create and manage VBR connections by using Alibaba Cloud SDKs (recommended), CLI, Terraform, or ROS. Relevant APIs:

  • CreateTransitRouterVbrAttachment: Create a VBR connection on an Enterprise Edition transit router.

  • UpdateTransitRouterVbrAttachmentAttribute: Update a VBR connection on an Enterprise Edition transit router.

  • ReplaceTransitRouterRouteTableAssociation: Associate a connection with a different transit router route table.

  • AttachCenChildInstance: Connect a VBR to a Basic Edition transit router.