Apex domains cannot have CNAME records.
Question and response
Question
dig ntf-server.net. NS
Answer
ntf-server.net. 4 NS dns2.nsdns.info.
ntf-server.net. 4 NS dns1.nsdns.info.
ntf-server.net. 4 NS dns3.nsdns.info.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0