Apex domains cannot have CNAME records.
Question and response
Question
dig via.com. NS
Answer
via.com. 5 NS a16-66.akam.net.
via.com. 5 NS a14-65.akam.net.
via.com. 5 NS a1-174.akam.net.
via.com. 5 NS a3-64.akam.net.
via.com. 5 NS a7-65.akam.net.
via.com. 5 NS a20-67.akam.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0