server-rwt-tx.static.cm2.net has no CNAME records.
Question and response
Question
dig server-rwt-tx.static.cm2.net. NS
Answer
The response has no answer records.
Authority
cm2.net. 2189 SOA ns1.erado.net. dnssupport.erado.com. 1772481721 16384 2048 1048576 2560
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0