51.91.138.210.xf.2iij.net has no NS records.
NS records for this zone are defined at 91.138.210.xf.2iij.net.
NS records for this zone are defined at 91.138.210.xf.2iij.net.
Question and response
Question
dig 51.91.138.210.xf.2iij.net. NS
Answer
The response has no answer records.
Authority
91.138.210.xf.2iij.net. 900 SOA dns-b.iij.ad.jp. dns-managers.iij.ad.jp. 1677672557 3600 1800 3600000 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0