c-24-91-35-31.hsd1.ma.comcast.net has no CNAME records.
Question and response
Question
dig c-24-91-35-31.hsd1.ma.comcast.net. NS
Answer
The response has no answer records.
Authority
hsd1.ma.comcast.net. 758 SOA dns101.comcast.net. dnsadmin.comcast.net. 15491911 7200 3600 604800 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0