Apex domains cannot have CNAME records.
Question and response
Question
dig ovh.net. NS
Answer
ovh.net. 5 NS dns13.ovh.net.
ovh.net. 5 NS ns13.ovh.net.
ovh.net. 5 NS ns15.ovh.net.
ovh.net. 5 NS dns10.ovh.net.
ovh.net. 5 NS dns11.ovh.net.
ovh.net. 5 NS ns10.ovh.net.
ovh.net. 5 NS ns11.ovh.net.
ovh.net. 5 NS dns15.ovh.net.
ovh.net. 5 NS ns12.ovh.net.
ovh.net. 5 NS dns12.ovh.net.
Authority
The response has no authority records.
Additional
ns10.ovh.net. 5 A 5.39.20.253
ns11.ovh.net. 5 A 5.39.27.169
ns12.ovh.net. 5 A 5.39.102.21
ns13.ovh.net. 5 A 5.39.112.241
ns15.ovh.net. 5 A 5.39.114.9
dns10.ovh.net. 5 A 5.135.85.109
dns11.ovh.net. 5 A 5.135.86.61
dns12.ovh.net. 5 A 5.135.86.81
dns13.ovh.net. 5 A 5.135.98.29
dns15.ovh.net. 5 A 5.135.110.101
ns10.ovh.net. 5 AAAA 2001:41d0:b00:3a00:0:0:0:2
ns11.ovh.net. 5 AAAA 2001:41d0:b00:d000:0:0:0:2
ns12.ovh.net. 5 AAAA 2001:41d0:b00:eb00:0:0:0:2
ns13.ovh.net. 5 AAAA 2001:41d0:b00:ec00:0:0:0:2
ns15.ovh.net. 5 AAAA 2001:41d0:b00:ee00:0:0:0:2
dns10.ovh.net. 5 AAAA 2001:41d0:d00:6100:0:0:0:2
dns11.ovh.net. 5 AAAA 2001:41d0:d00:f000:0:0:0:2
dns12.ovh.net. 5 AAAA 2001:41d0:d00:f100:0:0:0:2
dns13.ovh.net. 5 AAAA 2001:41d0:d00:f200:0:0:0:2
dns15.ovh.net. 5 AAAA 2001:41d0:d00:f400:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0