Apex domains cannot have CNAME records.
Question and response
Question
dig virtualtec.ch. NS
Answer
virtualtec.ch. 3 NS ns1.virtualtec.ch.
virtualtec.ch. 3 NS ns2.virtualtec.ch.
Authority
The response has no authority records.
Additional
ns1.virtualtec.ch. 3 A 93.189.64.6
ns2.virtualtec.ch. 3 A 93.189.66.16
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0