Apex domains cannot have CNAME records.
Question and response
Question
dig linuxhungary.com. NS
Answer
linuxhungary.com. 4 NS ns4.active-dns.com.
linuxhungary.com. 4 NS ns3.active-dns.com.
linuxhungary.com. 4 NS ns1.active-dns.com.
linuxhungary.com. 4 NS ns2.active-dns.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0