Apex domains cannot have CNAME records.
Question and response
Question
dig dns1.netsons.net. NS
Answer
dns1.netsons.net. 1 NS dns1.netsons.net.
dns1.netsons.net. 1 NS dns3.netsons.net.
dns1.netsons.net. 1 NS dns2.netsons.net.
dns1.netsons.net. 1 NS dns4.netsons.net.
Authority
The response has no authority records.
Additional
dns1.netsons.net. 1 A 46.252.159.53
dns2.netsons.net. 1 A 46.252.159.54
dns3.netsons.net. 1 A 51.195.116.88
dns4.netsons.net. 1 A 51.255.173.224
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0