dns1.commcorp.net.br has no CNAME records.
Question and response
Question
dig dns1.commcorp.net.br. NS
Answer
The response has no answer records.
Authority
commcorp.net.br. 3456 SOA dns1.commcorp.net.br. postmaster.commcorp.com.br. 2026012758 7200 900 1296000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0