ns4.apa.net has no NS records.
NS records for this zone are defined at apa.net.
NS records for this zone are defined at apa.net.
Question and response
Question
dig ns4.apa.net. NS
Answer
The response has no answer records.
Authority
apa.net. 30 SOA ns2.apa.at. domain-admin.apa.at. 2026031102 10800 3600 604800 30
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0