DigitalOcean Reserved IP addresses are a publicly-accessible static IP addresses. Assign and reassign reserved IP addresses to Droplets as needed, or implement a failover mechanism with reserved IPs to build a high availability infrastructure.
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.
You can use reserved IPs to create server infrastructures without single points of failure, but a reserved IP alone does not automatically provide high availability. For a setup to be highly available, you need to implement a failover mechanism to automate the process of detecting failures of the active server and reassigning the reserved IP to a passive server.
For example, you can assign a reserved IP to a Droplet that is running a web application. You can then write a script that uses the DigitalOcean Monitoring API to monitor the Droplet’s performance and then reassign the IP address to a backup Droplet (using the API) if the original Droplet’s performance becomes unstable or poor.