Digital Ocean recently released private networking support in their NYC2 Data center.
They also published a blog post on how to setup a new droplet with private networking. But one thing the post doesn't do is tell you how to scale your private network for many boxes. One approach is obviously to edit /etc/hosts (but this gets annoying when you add a new box). A better way is to create an internal DNS zone (via the digital ocean web interface) and have your droplets use it:
setup the internal DNS zone file
- Login to digital ocean
- Click "DNS" on the right hand menu