I recently had a scenario where I needed to connect servers belonging to: - Digitalocean , on data center X - Digitalocean, on data center Y - A private data center and each architecture needed to be replicated on a number of "logical" environments (e.g. 'development', 'testing', 'production'). They needed to "see" each other, in a secure way. Note that virtual machines on Digitalocean (they call them 'droplets') can belong to different data centers. When the droplets use the optional private interface there are two things to consider: 1. Traffic inside the same data center is potentially visible to any equipment on the same data center. In other words, the fact that two droplets belong to the same customer account doesn't mean that their private traffic is isolated from any other traffic belonging to droplets on other accounts. You are responsible to secure that traffic. 2. Droplets on different data centers cannot ...