Honestly I never found a briowser that didn't support multiple a record failover. Older versions of ie mostly. You do need to be aware that many nameservers wil

Honestly I never found a briowser that didn't support multiple a record failover. Older versions of ie mostly. You do need to be aware that many nameservers will reorder a records by integer sort or delta to their own IP, which can make your traffic pattern uneven. There are various managed DNS products to handle that, and you can build it yourself with enough time.