dns1.telekom.de has no NS records.
NS records for this zone are defined at telekom.de.
NS records for this zone are defined at telekom.de.
Question and response
Question
dig dns1.telekom.de. NS
Answer
The response has no answer records.
Authority
telekom.de. 600 SOA dns1.telekom.de. dnsadmin.t-systems.com. 2019037953 10800 1800 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0