Apex domains cannot have CNAME records.
Question and response
Question
dig static.brasov.rdsnet.ro. NS
Answer
static.brasov.rdsnet.ro. 2 NS ns1.rdsnet.ro.
static.brasov.rdsnet.ro. 2 NS ns2.rdsnet.ro.
Authority
The response has no authority records.
Additional
ns1.rdsnet.ro. 2 A 193.231.236.17
ns2.rdsnet.ro. 2 A 193.231.236.10
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0