@jcust

IIRC, Floating IP’s are primarily designed for use with load-balanced configurations and working with DigitalOceans’ API since the API allows you to automate the process without logging in to the CP.

While I understand what you’re trying to do, doing it with two Droplets (or servers in general) is less than ideal and results in more work than should be required to manage (whether that’s clear now or not).

When it comes to redundancy configuration, load balancing is the answer as it eliminates the need for such a configuration (as provided in your example). Droplet A serves as a Load Balancer while Droplet B and Droplet C serve as the Load Balanced recipients of requests routed from the Load Balancer. To go a step further, Droplet A and Droplet B are Load Balancers and Droplet C and Droplet D are the Load Balanced recipients (thus providing redundancy to both).

In either case, whether you’re using 3 Droplets or 4 Droplets, you still only need a single Floating IP which would be assigned to Droplet A. Droplet A then routes requests to the configured recipients which are verified at a specified interval, prior to sending traffic.

In the case of the 4 Droplet configuration, using the API is really going to be the best way to achieve any level of automation while reducing the work involved in rerouting. In either case, however, neither require more than a single Floating IP to achieve the intended redundancy as the only configuration that depends on an IP change would be the Load Balancers as they handle which server receives the incoming request, thus assigning a Floating IP to the web server would be pointless and simply add another IP to the list of required assets to manage.

As for IP usage – IP usage is IP usage at the end of the day. If every Droplet used the same setup as used in your example, DigitalOcean would be providing countless IP’s to customers that fall outside of what is defined as “justified use” in the eyes of ARIN/RIPE. Using “I don’t want to set up another server as a load balancer or [insert similar]” isn’t justification and if that was the given explanation from DO, another provider or by someone with their own assignment, they’d most likely receive a notice that requests/demands valid usage.