mx.ipng.com.au has no NS records.
NS records for this zone are defined at ipng.com.au.
NS records for this zone are defined at ipng.com.au.
Question and response
Question
dig mx.ipng.com.au. NS
Answer
The response has no answer records.
Authority
ipng.com.au. 300 SOA sy4.dns.ipng.net.au. hostmaster.ipng.net.au. 2026010201 10800 3600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0