Apex domains cannot have CNAME records.
Question and response
Question
dig netmng.com. NS
Answer
netmng.com. 4 NS ns1-23.akam.net.
netmng.com. 4 NS eur6.akam.net.
netmng.com. 4 NS aus1.akam.net.
netmng.com. 4 NS asia3.akam.net.
netmng.com. 4 NS eur5.akam.net.
netmng.com. 4 NS usw6.akam.net.
netmng.com. 4 NS eur2.akam.net.
netmng.com. 4 NS ns1-200.akam.net.
Authority
The response has no authority records.
Additional
asia3.akam.net. 4 A 23.211.61.64
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0