[escalt]

On IPv6 this would be a solved issue. With SLAAC the router just broadcasts Router Advertisements and all the machines just automatically configure their addresses, which are fully predictable based on their MAC address (if you have privacy extensions disabled). The router has no state to keep and as such the network can be scaled up "infinitely". Just pick a random /64 prefix and set up radvd (or systemd-networkd) to send the router advertisements.

[latchkey]

Sure. The thing is that we also have a physical location based naming system which is somewhat tied to the IPv4 address and we use that system across multiple data centers. We also have a single daemon running on each box that helps with the naming. It would complicate things (ie: more code to write) to have one dc (where we had these issues), on IPv6. We hadn't had issues before, so it never really made sense to use IPv6 other than for the novelty of it. IPv4 works surprisingly well and the issue really wasn't at that layer. Who knows too.. maybe radvd or systemd-networkd also have other issues we don't know about.