slc19.slc.efscloud.net has no CNAME records.
Question and response
Question
dig slc19.slc.efscloud.net. NS
Answer
The response has no answer records.
Authority
efscloud.net. 885 SOA ns1.efscloud.net. efscloud.net.domainsbyproxy.com. 393 600 300 3600000 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0