nomail.IX.RU has no NS records.
NS records for this zone are defined at IX.RU.
NS records for this zone are defined at IX.RU.
Question and response
Question
dig nomail.IX.RU. NS
Answer
The response has no answer records.
Authority
ix.ru. 3600 SOA ns.msk-ix.ru. noc-dns.msk-ix.ru. 650146688 86400 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0