Apex domains cannot have CNAME records.
Question and response
Question
dig switch.ch. NS
Answer
switch.ch. 5 NS ns3.switch.ch.
switch.ch. 5 NS scsnms.switch.ch.
switch.ch. 5 NS ns2.switch.ch.
Authority
The response has no authority records.
Additional
ns2.switch.ch. 5 A 130.59.31.29
ns3.switch.ch. 5 A 194.58.198.32
scsnms.switch.ch. 5 A 130.59.31.26
ns2.switch.ch. 5 AAAA 2001:620:0:ff:0:0:0:2f
ns3.switch.ch. 5 AAAA 2a01:3f1:3032:0:0:0:0:53
scsnms.switch.ch. 5 AAAA 2001:620:0:ff:0:0:0:a7
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0