Apex domains cannot have CNAME records.
Question and response
Question
dig NCPORT.RU. NS
Answer
ncport.ru. 5 NS ns1.ncport.ru.
ncport.ru. 5 NS ns2.ncport.ru.
Authority
The response has no authority records.
Additional
ns1.ncport.RU. 5 A 92.60.92.182
ns2.ncport.RU. 5 A 213.134.195.253
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0