alpha1.rdrhost.com has no CNAME records.
Question and response
Question
dig alpha1.rdrhost.com. NS
Answer
The response has no answer records.
Authority
rdrhost.com. 1719 SOA ns.gransy.com. root.gransy.com. 2772118360 86400 900 1209600 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0