rubys.sysdop.com has no CNAME records.
Question and response
Question
dig rubys.sysdop.com. NS
Answer
The response has no answer records.
Authority
sysdop.com. 1677 SOA aragorn.ns.cloudflare.com. dns.cloudflare.com. 2397631424 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0