collab.cert.fi has no CNAME records.
Question and response
Question
dig collab.cert.fi. NS
Answer
The response has no answer records.
Authority
cert.fi. 3374 SOA dns1.ficora.fi. hostmaster.ficora.fi. 2026022316 3600 900 5356800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0