root-dns.netcup.net has no NS records.
NS records for this zone are defined at netcup.net.
NS records for this zone are defined at netcup.net.
Question and response
Question
dig root-dns.netcup.net. NS
Answer
The response has no answer records.
Authority
netcup.net. 7200 SOA acns01.xaas.systems. mail.netcup.de. 3578 14400 1800 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0