Apex domains cannot have CNAME records.
Question and response
Question
dig dnet.ovh. NS
Answer
dnet.ovh. 1 NS dns110.ovh.net.
dnet.ovh. 1 NS ns110.ovh.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0