d.dns.RIPN.net has no NS records.
NS records for this zone are defined at RIPN.net.
NS records for this zone are defined at RIPN.net.
Question and response
Question
dig d.dns.RIPN.net. NS
Answer
The response has no answer records.
Authority
RIPN.net. 1800 SOA a.dns.RIPN.net. noc-dns.msk-ix.ru. 27013605 14400 3600 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0