Apex domains cannot have CNAME records.
Question and response
Question
dig njv.avantel.ru. NS
Answer
njv.avantel.ru. 5 NS ns.njv.avantel.ru.
njv.avantel.ru. 5 NS ns.avantel.ru.
Authority
The response has no authority records.
Additional
ns.njv.avantel.ru. 5 A 91.203.9.2
ns.avantel.RU. 5 A 195.49.168.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0