Apex domains cannot have CNAME records.
Question and response
Question
dig ioflood.net. NS
Answer
ioflood.net. 5 NS ns2.ioflood.com.
ioflood.net. 5 NS ns1.ioflood.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0