Reserved IP Details

A DigitalOcean Reserved IP address is a publicly-accessible static IP address that you can assign to a Droplet and then reassign to another Droplet later, as needed. You can implement a failover mechanism with reserved IPs to build a high availability infrastructure.

Note
The Floating IP service is now called Reserved IPs. The Reserved IP service retains the same functionality as the prior service.

Reserved IPs let you redirect network traffic between any of your Droplets within the same datacenter. Assigning a reserved IP to a Droplet doesn’t replace or change its original public IP address.
Reserved IPs are free when assigned to a Droplet.
Reserved IPs are available in all datacenters. They are region-specific resources and can only be assigned to Droplets within the same datacenter.
Limits and known issues for Reserved IPs.