unknown.twcable.com has no CNAME records.
Question and response
Question
dig unknown.twcable.com. NS
Answer
The response has no answer records.
Authority
twcable.com. 3208 SOA ns1.twcable.com. hostmaster.pblpdns01.twcable.com. 2026012003 14400 7200 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0