firewall.alonsa.cl has no CNAME records.
Question and response
Question
dig firewall.alonsa.cl. NS
Answer
The response has no answer records.
Authority
alonsa.cl. 3067 SOA dns.alonsa.cl. informatica.alonsa.cl. 2025080600 43200 7200 2419200 43200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0