Apex domains cannot have CNAME records.
Question and response
Question
dig eth-services.de. NS
Answer
eth-services.de. 5 NS dos.eth-services.de.
eth-services.de. 5 NS cinco.eth-services.de.
eth-services.de. 5 NS cuatro.eth-services.de.
eth-services.de. 5 NS uno.eth-services.de.
eth-services.de. 5 NS tres.eth-services.de.
Authority
The response has no authority records.
Additional
dos.eth-services.de. 5 A 2.58.52.137
uno.eth-services.de. 5 A 5.1.84.126
tres.eth-services.de. 5 A 185.254.97.40
cinco.eth-services.de. 5 A 85.215.133.143
cuatro.eth-services.de. 5 A 178.251.228.213
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0