ns2.brava.inf.br has no CNAME records.
Question and response
Question
dig ns2.brava.inf.br. NS
Answer
The response has no answer records.
Authority
brava.inf.br. 3600 SOA ns1.brava.inf.br. root.brava.inf.br. 2026012763 4800 3600 1209600 6000
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0