Apex domains cannot have CNAME records.
Question and response
Question
dig is74.ru. NS
Answer
is74.ru. 5 NS ns2.is74.ru.
is74.ru. 5 NS ns1.is74.ru.
Authority
The response has no authority records.
Additional
ns1.is74.ru. 5 A 83.142.161.17
ns2.is74.RU. 5 A 83.142.160.155
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0