Apex domains cannot have CNAME records.
Question and response
Question
dig a8.net. NS
Answer
a8.net. 5 NS ns-888.awsdns-47.net.
a8.net. 5 NS ns-2044.awsdns-63.co.uk.
a8.net. 5 NS ns-124.awsdns-15.com.
a8.net. 5 NS ns-1261.awsdns-29.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0