Apex domains cannot have CNAME records.
Question and response
Question
dig fti.net. NS
Answer
fti.net. 5 NS ns3.fti.net.
fti.net. 5 NS ns6.fti.net.
fti.net. 5 NS ns5.fti.net.
fti.net. 5 NS ns2.fti.net.
fti.net. 5 NS ns1.fti.net.
fti.net. 5 NS ns4.fti.net.
Authority
The response has no authority records.
Additional
ns1.fti.net. 5 A 193.252.148.163
ns2.fti.net. 5 A 193.252.148.164
ns3.fti.net. 5 A 193.252.121.121
ns4.fti.net. 5 A 193.252.121.124
ns5.fti.net. 5 A 81.52.142.245
ns6.fti.net. 5 A 81.52.142.244
ns1.fti.net. 5 AAAA 2a01:c9c0:a3:8:0:0:0:11
ns2.fti.net. 5 AAAA 2a01:c9c0:a3:8:0:0:0:12
ns3.fti.net. 5 AAAA 2a01:c9c0:b3:3000:0:0:0:13
ns4.fti.net. 5 AAAA 2a01:c9c0:b3:3000:0:0:0:14
ns5.fti.net. 5 AAAA 2a01:c9c0:c3:229:0:0:0:23
ns6.fti.net. 5 AAAA 2a01:c9c0:c3:229:0:0:0:22
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0