f.nic.de has no NS records.
NS records for this zone are defined at nic.de.
NS records for this zone are defined at nic.de.
Question and response
Question
dig f.nic.de. NS
Answer
The response has no answer records.
Authority
nic.de. 1800 SOA ns1.denic.de. dns-operations.denic.de. 1771933561 10800 1800 3600000 1800
Additional
. 0 OPT ; payload 1452, xrcode 0, version 0, flags 0