Apex domains cannot have CNAME records.
Question and response
Question
dig ht.ok.shawcable.net. NS
Answer
ht.ok.shawcable.net. 5 NS ns4.st.vc.shawcable.net.
ht.ok.shawcable.net. 5 NS ns1.ht.ok.shawcable.net.
Authority
The response has no authority records.
Additional
ns1.ht.ok.shawcable.net. 4 A 64.59.168.50
ns1.ht.ok.shawcable.net. 4 AAAA 2001:4e8:0:400d:0:0:53:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0