Apex domains cannot have CNAME records.
Question and response
Question
dig dnns.net. NS
Answer
dnns.net. 5 NS ns2.dnns.net.
dnns.net. 5 NS ns1.dnns.net.
Authority
The response has no authority records.
Additional
ns1.dnns.net. 5 A 66.128.53.40
ns2.dnns.net. 5 A 66.36.228.217
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0