it's unclear to me how to renumber a server that *only* has a record in LDAP (as opposed to something in `dns/domains.git` as well). in legacy/trac#33730, the DNS records were not picked up by nevii, the authoritative nameserver, even after running `ud-generate` on alberti and `ud-replicate` on nevii. and indeed, those commands only populate `/var/lib/misc/` on nevii, which doesn't touch the full zone loaded by bind. so this needs clarification and documentation and aaargh.