Apex domains cannot have CNAME records.
Question and response
Question
dig dcvolia.com. NS
Answer
dcvolia.com. 5 NS ns1.dcvolia.com.
dcvolia.com. 5 NS ns0.dc.volia.com.
dcvolia.com. 5 NS ns5.dc.volia.com.
dcvolia.com. 5 NS ns1.dc.volia.com.
dcvolia.com. 5 NS ns1.volia.net.
Authority
The response has no authority records.
Additional
ns1.volia.net. 5 A 82.144.192.40
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0