rt1.noanet.net has no CNAME records.
Question and response
Question
dig rt1.noanet.net. NS
Answer
The response has no answer records.
Authority
noanet.net. 7200 SOA ns1.noanet.net. hostmaster.noanet.net. 2026022301 900 7200 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0