Floating IP reassignment and connection handling during same-datacenter Droplet migration

The goal is to migrate a small application to a replacement Droplet in the same DigitalOcean datacenter by moving a Floating IP, avoiding DNS propagation and user-facing downtime.

The reassignment is a control-plane action. Existing TCP connections to the original Droplet are dropped rather than gracefully drained, and Floating IPs do not fail over automatically. The move is datacenter-scoped, so the replacement Droplet must reside in the same region. Firewall rules on the target Droplet must permit traffic on the Floating IP ports before cutover.

Because no incident or error was observed, this is a design question about the connection and networking boundary.

• Are active TCP sessions terminated immediately when a Floating IP is reassigned, or does any connection-draining behavior apply?
• Does the target Droplet begin accepting Floating IP traffic immediately after reassignment, or are additional firewall or networking changes required?
• Does the same-datacenter constraint prevent zero-downtime migration across regions?