Apex domains cannot have CNAME records.
Question and response
Question
dig surf.nl. NS
Answer
surf.nl. 3 NS ns3.surfnet.nl.
surf.nl. 3 NS ns2.surfnet.nl.
surf.nl. 3 NS ns1.zurich.surf.net.
surf.nl. 3 NS ns1.surfnet.nl.
Authority
The response has no authority records.
Additional
ns1.zurich.surf.net. 3 A 195.176.255.9
ns1.surfnet.nl. 3 A 192.87.106.101
ns2.surfnet.nl. 3 A 192.87.36.2
ns3.surfnet.nl. 3 A 195.169.124.71
ns1.zurich.surf.net. 3 AAAA 2001:620:0:9:0:0:0:1103
ns1.surfnet.nl. 3 AAAA 2001:610:1:800a:192:87:106:101
ns2.surfnet.nl. 3 AAAA 2001:610:3:200a:192:87:36:2
ns3.surfnet.nl. 3 AAAA 2001:610:0:800c:195:169:124:71
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0