dns1.telstra.net has no CNAME records.
Question and response
Question
dig dns1.telstra.net. NS
Answer
The response has no answer records.
Authority
telstra.net. 1405 SOA dns0.telstra.net. hostmaster.telstra.net. 2021177538 10800 3600 604800 6400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0