Apex domains cannot have CNAME records.
Question and response
Question
dig pork3.net. NS
Answer
pork3.net. 5 NS ns-178.awsdns-22.com.
pork3.net. 5 NS ns-340.awsdns-42.com.
pork3.net. 5 NS ns-698.awsdns-23.net.
pork3.net. 5 NS ns-1226.awsdns-25.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0