ns.sbs.de has no CNAME records.
Question and response
Question
dig ns.sbs.de. NS
Answer
The response has no answer records.
Authority
sbs.de. 3600 SOA david.siemens.de. dnsmaster.atos.net. 2026022617 900 300 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0