Apex domains cannot have CNAME records.
Question and response
Question
dig siberia.net. NS
Answer
siberia.net. 5 NS b.ns.avantel.ru.
siberia.net. 5 NS a.ns.avantel.ru.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0