Apex domains cannot have CNAME records.
Question and response
Question
dig as9143.net. NS
Answer
as9143.net. 5 NS ns3.as9143.net.
as9143.net. 5 NS ns1.as9143.net.
Authority
The response has no authority records.
Additional
ns1.as9143.net. 5 A 212.54.45.156
ns3.as9143.net. 5 A 212.54.43.236
ns1.as9143.net. 5 AAAA 2001:b88:1002:1570:0:0:0:11
ns3.as9143.net. 5 AAAA 2001:b88:1202:1570:0:0:0:11
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0