When the system detects a failure in an Express Connect circuit, the system performs a failover. The time required to complete a failover is approximately 5 seconds. To accelerate failovers, you can create a failover group that consists of two virtual border routers (VBRs). After the system detects failures of the active VBR by using Bidirectional Forwarding Detection (BDF), the system can seamlessly switch workloads to the standby VBR in the failover group within less than one second.

Limits

Failover groups have the following limits:
  • To use failover groups: Submit a ticket.
  • You can add only VBRs that have BFD enabled to failover groups.
  • Each failover group can contain only two VBRs and each VBR can belong only to one failover group.
  • The VBRs in a failover group must be deployed in the same region and attached to the same Cloud Enterprise Network (CEN) instance.
  • The BGP peer groups of the VBRs in a failover group must use the same Autonomous System (AS) number.

Prerequisites

  • Two VBRs are created in the same region and each VBR is connected to your data center through an Express Connect circuit. For more information, see Create a VBR and Add routes.
  • The VBRs are attached to the same CEN instance. For more information, see Attach networks.
  • BFD is enabled for the VBRs. For more information, see Configure BGP.

Create a failover group

  1. Log on to the Express Connect console.
  2. In the top navigation bar, select the region and click Virtual Border Routers (VBRs) in the left-side navigation pane.
  3. On the Virtual Border Routers (VBRs) page, click the ID of the VBR that you want to manage.
  4. On the VBR details page, click the Failover Groups tab, and click Configure Backup Next Hop.
  5. In the Configure Backup Next Hop dialog box, set the following parameters and click OK:
    • CEN: The system automatically displays the CEN instance to which the VBR is attached. If the VBR is not attached to a CEN instance, click Attach Now to attach the VBR to a CEN instance.
    • Region: The system automatically displays the region where the VBR is deployed.
    • Failover Group Name: Enter a name for the failover group.

      The value must be 2 to 128 characters in length, and can contain digits, underscores (_), and hyphens (-). It must start with a letter and cannot start with http:// or https://.

    • Description: Enter a description for the failover group.
    • Standby VBR: Specify the standby VBR. The system automatically lists all VBRs that are deployed in the same region, attached to the same CEN instance, and have BFD enabled.

    After you complete the preceding steps, the state of the failover group changes to Normal.

    Note You cannot modify the configurations of a failover group after the failover group is created. If you want to modify a failover group, you must click Delete in the Actions column to delete the failover group. Then, recreate the failover group.

Verify the results

After you complete the preceding steps, you can perform the following operations to test the configurations:

  1. Log on to the Elastic Compute Service (ECS) instance. For more information, see Overview.
  2. Run the ping command on the ECS instance to check the connectivity between the ECS instance and your data center.
    If the ECS instance can receive echo reply packets, it indicates that the connection is established.
  3. Disconnect the active VBR from the data center.
  4. Run the ping command again on the ECS instance to check the connectivity between the ECS instance and your data center.
    If the ECS instance can receive echo reply packets, it indicates that the connection has been switched to the standby VBR in the failover group.