With DNS Failover, Amazon Route 53 can help detect an outage of your website and redirect yourend users to alternate locations where your application is operating properly. When you enable thisfeature, Route 53 uses health checks--regularly making Internet requests to your application'sendpoints from multiple locations around the world--to determine whether each endpoint of yourapplication is up or down. To enable DNS Failover for an ELB endpoint, create an Alias recordpointing to the ELB and set the "Evaluate Target Health" parameter to true. Route 53 creates andmanages the health checks for your ELB automatically. You do not need to create your own Route 53health check of the ELB. You also do not need to associate your resource record set for the ELB withyour own health check, because Route 53 automatically associates it with the health checks thatRoute 53 manages on your behalf. The ELB health check will also inherit the health of your backendinstances behind that ELB. Reference: http://aws.amazon.com/about-aws/whats-new/2013/05/30/amazon-route-53-adds-elbintegration-for-dns-failover/