o7.ptr851.adversus.io has no CNAME records.
Question and response
Question
dig o7.ptr851.adversus.io. NS
Answer
The response has no answer records.
Authority
adversus.io. 3584 SOA ns1.dlx.dk. ks.dlx.dk. 2025101003 14400 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0