dns01.providerbox.de has no NS records.
NS records for this zone are defined at providerbox.de.
NS records for this zone are defined at providerbox.de.
Question and response
Question
dig dns01.providerbox.de. NS
Answer
The response has no answer records.
Authority
providerbox.de. 900 SOA dns01.providerbox.de. dnsadmin\@providerbox.de. 1736513396 900 1800 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0