dns1.telstra.net has no NS records.
NS records for this zone are defined at telstra.net.
NS records for this zone are defined at telstra.net.
Question and response
Question
dig dns1.telstra.net. NS
Answer
The response has no answer records.
Authority
telstra.net. 6400 SOA dns0.telstra.net. hostmaster.telstra.net. 2021177581 10800 3600 604800 6400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0