core0.fmt1.ntfo.org has no CNAME records.
Question and response
Question
dig core0.fmt1.ntfo.org. NS
Answer
The response has no answer records.
Authority
fmt1.ntfo.org. 10373 SOA ntfo.org. postmaster.ntfo.org. 2026011700 86400 14400 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0