ns6.checon.de has no CNAME records.
Question and response
Question
dig ns6.checon.de. NS
Answer
The response has no answer records.
Authority
checon.de. 10759 SOA ns.checon.net. hostmaster.checon.de. 2025071001 28800 3600 864000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0