A static, publicly accessible IPv4 address that can be assigned to any Droplet in a DigitalOcean region and instantly reassigned to another Droplet. Reserved IPs enable failover architectures where traffic is redirected from a failing Droplet to a standby by reassigning the IP — with DNS changes propagating in seconds rather than minutes.
A high-availability web application uses a Reserved IP as its public endpoint. When the active Droplet fails its health check, an automated script reassigns the Reserved IP to the standby Droplet via the DigitalOcean API. DNS records do not need to change, and traffic redirects in under 30 seconds.