dns2.advance.com.ar has no CNAME records.
Question and response
Question
dig dns2.advance.com.ar. NS
Answer
The response has no answer records.
Authority
advance.com.ar. 600 SOA dns1.advance.com.ar. dominios.advance.com.ar. 2025081401 3600 1800 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0