Apex domains cannot have CNAME records.
Question and response
Question
dig vlq16.iliad.fr. NS
Answer
vlq16.iliad.fr. 5 NS ns0.vlq16.iliad.fr.
vlq16.iliad.fr. 5 NS ns2.iliad.fr.
vlq16.iliad.fr. 5 NS ns1.vlq16.iliad.fr.
Authority
The response has no authority records.
Additional
ns0.vlq16.iliad.fr. 5 A 213.36.7.21
ns1.vlq16.iliad.fr. 5 A 213.36.7.22
ns2.iliad.fr. 5 A 212.83.164.80
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0