Apex domains cannot have CNAME records.
Question and response
Question
dig packetfault.org. NS
Answer
packetfault.org. 4 NS ns-825.awsdns-39.net.
packetfault.org. 4 NS ns-1962.awsdns-53.co.uk.
packetfault.org. 4 NS ns-978.awsdns-58.net.
packetfault.org. 4 NS ns-901.awsdns-48.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0