Apex domains cannot have CNAME records.
Question and response
Question
dig esc.net.au. NS
Answer
esc.net.au. 5 NS ns1.esc.net.au.
esc.net.au. 5 NS ns3.esc.net.au.
esc.net.au. 5 NS ns2.esc.net.au.
esc.net.au. 5 NS ns4.esc.net.au.
Authority
The response has no authority records.
Additional
ns1.esc.net.au. 5 A 203.25.185.1
ns2.esc.net.au. 5 A 203.25.185.2
ns3.esc.net.au. 5 A 210.56.80.45
ns4.esc.net.au. 5 A 107.170.203.252
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0