Web+bd failover 2 data center?

Question

High availability

There are four servers in two data centers, 2 in each. Spinning on one iis host on another mssql. I would like to failover in case of a data center crash. I thought about amazon route53 dns failover, but after reading that browsers cache dns records for an hour, I began to doubt this option. Data centers have different ip subnets, different addresses. It seems that if you implement bgp, then you can live with one address. Is it difficult to do this? What other options are there?