spf.dtu.dk has no NS records.
NS records for this zone are defined at dtu.dk.
NS records for this zone are defined at dtu.dk.
Question and response
Question
dig spf.dtu.dk. NS
Answer
The response has no answer records.
Authority
dtu.dk. 900 SOA ait-pibgm01.win.dtu.dk. dnsadmin.dtu.dk. 2022100836 10800 3600 2419200 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0