server10.virtualhosts.de has no CNAME records.
Question and response
Question
dig server10.virtualhosts.de. NS
Answer
The response has no answer records.
Authority
virtualhosts.de. 737 SOA ns1.virtualhosts.de. hostmaster.virtualhosts.de. 2026020578 7200 3600 604800 1000
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0