ns2.dtst.de has no CNAME records.
Question and response
Question
dig ns2.dtst.de. NS
Answer
The response has no answer records.
Authority
dtst.de. 3246 SOA ns1.swiss-dns.com. service.dtst.de. 2025030401 14400 7200 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0