e5.a3.089f.ip4.static.sl-reverse.com has no CNAME records.
Question and response
Question
dig e5.a3.089f.ip4.static.sl-reverse.com. NS
Answer
The response has no answer records.
Authority
ip4.static.sl-reverse.com. 10354 SOA ns1.arpa.networklayer.com. support.softlayer.com. 2018022300 7200 600 1728000 43200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0