customer.sparklight.com has no CNAME records.
Question and response
Question
dig customer.sparklight.com. NS
Answer
The response has no answer records.
Authority
sparklight.com. 900 SOA ns1.cableone.net. dnsadmin.cableone.net. 293 10800 3600 2592000 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0