ns2.snt.ru has no CNAME records.
Question and response
Question
dig ns2.snt.ru. NS
Answer
The response has no answer records.
Authority
snt.RU. 207 SOA ns1.snt.RU. dnsmaster.sinor.RU. 2025102503 86400 7200 1209600 345600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0