Apex domains cannot have CNAME records.
Question and response
Question
dig casscomm.com. NS
Answer
casscomm.com. 3 NS ns.casscomm.com.
casscomm.com. 3 NS ns2.casscomm.com.
casscomm.com. 3 NS web.casscabletv.com.
Authority
The response has no authority records.
Additional
ns.casscomm.com. 3 A 24.245.95.11
ns2.casscomm.com. 3 A 24.245.95.17
web.casscabletv.com. 3 A 24.245.95.15
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0