Apex domains cannot have CNAME records.
Question and response
Question
dig abdns.net. NS
Answer
abdns.net. 5 NS ns1.abdns.net.
abdns.net. 5 NS ns2.abdns.net.
Authority
The response has no authority records.
Additional
ns1.abdns.net. 5 A 94.177.186.71
ns2.abdns.net. 5 A 89.46.76.73
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0