A banking organization has hybrid connectivity for its 3-tier application. They have set up redundant AWS Direct Connect links from DataCenter to AWS. Last week, a connectivity issue where fiber cut at the service provider end resulted in an outage of primary link & traffic was shifted to secondary after a long delay. This resulted in the failure of many banking transactions & financial loss.
After troubleshooting, it was found that traffic sent over primary link even after fiber cut & was getting blackholed. IT head is looking for an immediate solution to this problem to avoid such instances in the future. Which of the following solution can be deployed in a quick way?

Answer options:

A.Enable BFD at Customer end Router on physical interface & open an AWS Support Ticket to enable BFD at AWS end.
B.Enable BFD at Customer end Router on a virtual interface.
C.Enable BFD at Customer end Router on virtual interface & open an AWS Support Ticket to enable BFD at AWS end.
D.Enable BFD at Customer end Router on the physical interface.

Correct Answer – B
BFD (Bidirectional forwarding detection) can be used to detect link failure & failover to secondary links faster. BFD is enabled for all AWS DX links & is activated once BFD is configured at the Customer End router. No additional changes are required on the AWS side for BFD configuration. At Customer Router, BFD is enabled on a virtual interface towards AWS.
Options A & Dare incorrect as BFD needs to add on the virtual interface & not on the physical interface.
Option C is incorrect as at the AWS end, BFD is already enabled & it takes effect once BFD is configured at the Customer end router.
For more information on using BFD, refer to the following URL
https://docs.aws.amazon.com/directconnect/latest/UserGuide/dc-ug.pdf
Please refer to the below link
https://aws.amazon.com/premiumsupport/knowledge-center/enable-bfd-direct-connect/