vmd163853.contaboserver.net has no CNAME records.
Question and response
Question
dig vmd163853.contaboserver.net. NS
Answer
The response has no answer records.
Authority
contaboserver.net. 3547 SOA ns1.contabo.net. hostmaster.contabo.de. 1771731405 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0