Apex domains cannot have CNAME records.
Question and response
Question
dig dedic-center.ru. NS
Answer
dedic-center.ru. 4 NS ns4.dedic-center.ru.
dedic-center.ru. 4 NS ns3.dedic-center.ru.
dedic-center.ru. 4 NS ns1.dedic-center.ru.
dedic-center.ru. 4 NS ns2.dedic-center.ru.
Authority
The response has no authority records.
Additional
ns1.dedic-center.ru. 4 A 91.221.71.4
ns2.dedic-center.ru. 4 A 91.221.71.5
ns1.dedic-center.ru. 4 AAAA 2a0b:e980:50:a:0:0:0:2
ns2.dedic-center.ru. 4 AAAA 2a0b:e980:50:a:0:0:0:3
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0