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Why do you mean by "proper"? I have a /64 with DO.
did you have to request the /64? unless it has changed or varies by datacenter, DO issues a /124 by default -- I've confirmed this on my own droplets just now. issuing a /64 is "proper" because it is RFC[1]. 1. https://tools.ietf.org/html/rfc3177
Super late reply, but I just wanted to correct myself. I don't have a /64 on DO. I was confusing my DO config with something else. I'm sorry about that. You are correct.