cns4.secureserver.net has no CNAME records.
Question and response
Question
dig cns4.secureserver.net. NS
Answer
The response has no answer records.
Authority
secureserver.net. 3600 SOA cns1.secureserver.net. dns.jomax.net. 2026022897 300 600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0