Apex domains cannot have CNAME records.
Question and response
Question
dig modem.beeline.ru. NS
Answer
modem.beeline.ru. 5 NS ns2.beeline.ru.
modem.beeline.ru. 5 NS ns1.beeline.ru.
Authority
The response has no authority records.
Additional
ns1.beeline.ru. 5 A 217.118.84.9
ns2.beeline.ru. 5 A 217.118.84.65
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0