A web application is deployed on an Amazon EC2 instance front-ended by Amazon ELB. Operations Head has asked you to perform DNS failover testing for this application.
Which settings can be done with Amazon Route 53 to meet this requirement?

Answer options:

A.Create an Alias record pointing to ELB & set the “Evaluate Target Health” parameter to true.
B.Create a CNAME record pointing to ELB & set the “Evaluate Target Health” parameter to true.
C.Create an Alias record pointing to ELB & associate resource record set for ELB with the health checks.
D.Create a CNAME record pointing to ELB & & associate resource record set for ELB with the health checks.

Correct Answer: A
DNS Failover can be configured for Amazon ELB. For this, an Alias record needs to be pointed at ELB, and “Evaluate Target Health” parameters need to be set as true. Based upon these settings, Route 53 creates and manages health checks for ELB automatically.
Options B and D are incorrect as for DNS failover ELB endpoint, alias record needs to be created, not the CNAME record.
Option C is incorrect as there is no need to associate resource record sets with the health check. This association is done automatically by Route 53.
For more information on DNS failover with ELB, refer to the following URL,
https://aws.amazon.com/route53/faqs/