us.confirmit.com has no CNAME records.
Question and response
Question
dig us.confirmit.com. NS
Answer
The response has no answer records.
Authority
confirmit.com. 6295 SOA udns1.cscdns.net. hostmaster.cscdns.net. 2018082968 10800 1800 1814400 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0