Apex domains cannot have CNAME records.
Question and response
Question
dig scs-ns.ch. NS
Answer
scs-ns.ch. 5 NS ns2.scs-ns.ch.
scs-ns.ch. 5 NS ns1.scs-ns.ch.
Authority
The response has no authority records.
Additional
ns1.scs-ns.ch. 5 A 194.209.158.65
ns2.scs-ns.ch. 5 A 194.209.159.65
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0