ns4.corpinter.de has no CNAME records.
Question and response
Question
dig ns4.corpinter.de. NS
Answer
The response has no answer records.
Authority
corpinter.de. 385 SOA ns1.corpinter.net. dnsadmin.mercedes-benz.com. 2007070200 10800 5400 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0