router02.i-tk.de has no CNAME records.
Question and response
Question
dig router02.i-tk.de. NS
Answer
The response has no answer records.
Authority
i-tk.de. 3600 SOA ns71.cloudns.net. admin.i-tk.de. 2026021302 7200 1800 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0