Apex domains cannot have CNAME records.
Question and response
Question
dig anycastdns.ch. NS
Answer
anycastdns.ch. 5 NS ns2.anycastdns.ch.
anycastdns.ch. 5 NS ns1.anycastdns.ch.
Authority
The response has no authority records.
Additional
ns1.anycastdns.ch. 5 A 192.174.68.104
ns2.anycastdns.ch. 5 A 176.97.158.104
ns1.anycastdns.ch. 5 AAAA 2001:67c:1bc:0:0:0:0:104
ns2.anycastdns.ch. 5 AAAA 2001:67c:10b8:0:0:0:0:104
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0