DNS/unbound/unbound.conf/local-data-ptrについて、ここに記述してください。

• local-data-ptr: "IPaddr name"
  • Configure local data shorthand for a PTR record with the reversed IPv4 or IPv6 address and the host name. For example "192.0.2.4 www.example.com". TTL can be inserted like this: "2001:DB8::4 7200 www.example.com"