> one normally-accessible SSH server per IP address With IPv6 this consideration is almost completely moot. > MX records Have fun with your MX not being port

> one normally-accessible SSH server per IP address With IPv6 this consideration is almost completely moot. > MX records Have fun with your MX not being port 25. > but most every other service requires a unique IP address per instance. This constant engineering overhead to play to the weaknesses of IPv4 is the problem.