When an Express Connect circuit fails, detecting the outage and switching routes typically takes several seconds. You can configure two Virtual Border Routers (VBRs) as a failover group to achieve sub-second recovery. When Bidirectional Forwarding Detection (BFD) detects a link failure, it automatically reroutes traffic from the VBR on the failed link to the standby VBR. This rapid failover accelerates route convergence and ensures business continuity.
Limitations
Only Virtual Border Routers (VBRs) with Bidirectional Forwarding Detection (BFD) enabled can be added to a failover group.
A failover group consists of exactly two VBRs. A VBR can belong to only one failover group.
The two VBRs in a failover group must be in the same region and attached to the same Express Connect Router (ECR) or Cloud Enterprise Network (CEN) instance.
If a VBR is already in a failover group, you must delete the existing failover group before you can configure a new one for the VBR.
The two VBRs in a failover group must form either an active-standby or a load balancing link relationship.
Prerequisites
You have created two Virtual Border Routers (VBRs) in the same region, each connected to your data center through a separate Express Connect circuit.
You have attached both VBRs to the same Express Connect Router (ECR) or Cloud Enterprise Network (CEN) instance.
You have enabled BFD for both VBRs.
Create a failover group
Log on to the Express Connect console.
In the top navigation bar, select the target region. In the left-side navigation pane, click Virtual Border Routers (VBRs).
On the Virtual Border Routers (VBRs) page, click the ID of a VBR instance.
On the instance details page, click the Failover Groups tab and then click Configure Backup Next Hop.
In the Configure Backup Next Hop dialog box, set the parameters and click OK.
Parameter
Description
Forwarding Gateway
The system automatically detects the ECR or CEN instance to which the current VBR is attached.
If the VBR is not attached to a forwarding gateway, click Attach Now and follow the on-screen instructions.
Region
The system automatically detects the region where the current VBR is located.
Failover Group Name
Enter a name for the failover group.
The name must be 2 to 128 characters long. It must start with a letter or a Chinese character, and can contain digits, underscores (_), and hyphens (-). The name cannot start with
http://orhttps://.Description
Enter a description for the failover group.
Standby VBR
Select the standby VBR.
The list shows all VBRs in the same region, attached to the same ECR or CEN instance, and with BFD enabled.
After the failover group is created, its status is Normal.
NoteYou cannot modify a failover group after it is created. If the configuration is incorrect, click Delete in the Actions column and then create a new one.
Verify the configuration
After you configure the failover group, perform the following steps to test the failover.
Log on to an ECS instance. For more information, see Connection methods.
On the ECS instance, run the
pingcommand to check connectivity between the ECS instance and your data center.Echo replies confirm the network connection is working as expected.
Disconnect the Express Connect circuit of the active VBR from your data center.
On the ECS instance, run the
pingcommand again to check connectivity between the ECS instance and your data center.Continued replies confirm that traffic has successfully failed over to the standby VBR.