serv37.cdns.net has no CNAME records.
Question and response
Question
dig serv37.cdns.net. NS
Answer
The response has no answer records.
Authority
cdns.net. 1285 SOA dns1.cdns.net. admin.communitydns.net. 1771734876 900 400 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0