auth1.charter.com has no CNAME records.
Question and response
Question
dig auth1.charter.com. NS
Answer
The response has no answer records.
Authority
charter.com. 3054 SOA ns1.charter.com. hostmaster.charter.com. 2026021626 43200 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0