Apex domains cannot have CNAME records.
Question and response
Question
dig cpcnet.com. NS
Answer
cpcnet.com. 2 NS ns1.hk.net.
cpcnet.com. 2 NS ns2.hk.net.
cpcnet.com. 2 NS ns11.hk.net.
cpcnet.com. 2 NS ns12.hk.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0