Apex domains cannot have CNAME records.
Question and response
Question
dig earthlink-vadesecure.net. NS
Answer
earthlink-vadesecure.net. 5 NS ns-1776.awsdns-30.co.uk.
earthlink-vadesecure.net. 5 NS ns-915.awsdns-50.net.
earthlink-vadesecure.net. 5 NS ns-326.awsdns-40.com.
earthlink-vadesecure.net. 5 NS ns-1090.awsdns-08.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0