51.20.139.133.staff.jp.ricoh.com has no NS records.
NS records for this zone are defined at staff.jp.ricoh.com.
NS records for this zone are defined at staff.jp.ricoh.com.
Question and response
Question
dig 51.20.139.133.staff.jp.ricoh.com. NS
Answer
The response has no answer records.
Authority
staff.jp.ricoh.com. 3600 SOA ns1.jp.ricoh.com. postmaster.ns1.jp.ricoh.com. 2025031005 3600 900 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0