After a connection over an Express Connect circuit is interrupted, you can use the failover feature of virtual border routers (VBRs). This feature allows you to switch to a connection that is working as expected and ensures that your services are not interrupted.

When a connection over an Express Connect circuit is interrupted, it typically takes 5 seconds for Bidirectional Forwarding Detection (BFD) to detect the interruption and switch routes. The failover feature allows a standby VBR to take over within seconds when BFD detects a failed VBR. This accelerates the convergence of routes and ensures that your services are not interrupted.
Note To use this feature, submit a ticket.

Procedure

You must first configure the active and standby connections between the virtual private cloud (VPC) and data center. After you verify that the connections can work as expected, configure the failover feature for two VBRs.

The following figure describes the procedure: Procedure

Limits

VBRs impose the following limits on the failover feature:
  • You can add only VBRs that have BFD enabled to failover groups.
  • You can add only two VBRs to each failover group.
  • You can add a VBR to only one failover group.
  • Two VBRs that are added to the same failover group must be attached to the same CEN instance and belong to the same region.
  • Each BGP group of the VBRs must be assigned the same autonomous system (AS) number. A VBR can have only one AS number.