df.uns.ac.rs has no CNAME records.
Question and response
Question
dig df.uns.ac.rs. NS
Answer
The response has no answer records.
Authority
uns.ac.rs. 3251 SOA ns1.uns.ac.rs. hostmaster.uns.ac.rs. 2025121800 43200 1800 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0