_netblocks2.mynet.at has no CNAME records.
Question and response
Question
dig _netblocks2.mynet.at. NS
Answer
The response has no answer records.
Authority
mynet.at. 3600 SOA adns1.mynet.at. hostmaster.mynet.at. 2026022401 14400 7200 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0