Apex domains cannot have CNAME records.
Question and response
Question
dig iliad.fr. NS
Answer
iliad.fr. 4 NS ns0.proxad.net.
iliad.fr. 4 NS ns1.iliad.fr.
iliad.fr. 4 NS ns-scw.proxad.net.
iliad.fr. 4 NS ns2.iliad.fr.
iliad.fr. 4 NS ns.iliad.fr.
iliad.fr. 4 NS ns1.proxad.net.
Authority
The response has no authority records.
Additional
ns.iliad.fr. 4 A 212.27.33.1
ns0.proxad.net. 5 A 212.27.32.2
ns1.iliad.fr. 4 A 212.27.33.3
ns1.proxad.net. 5 A 213.36.25.3
ns2.iliad.fr. 4 A 212.83.164.80
ns-scw.proxad.net. 5 A 62.210.100.46
ns0.proxad.net. 5 AAAA 2a01:e0c:1:1599:0:0:0:53
ns1.proxad.net. 5 AAAA 2a01:e0f:2:217:0:0:53:1
ns-scw.proxad.net. 5 AAAA 2001:bc8:1203:221:0:0:0:0
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0