Apex domains cannot have CNAME records.
Question and response
Question
dig jivesoftware.com. NS
Answer
jivesoftware.com. 2 NS ns-235.awsdns-29.com.
jivesoftware.com. 2 NS ns-745.awsdns-29.net.
jivesoftware.com. 2 NS ns-1349.awsdns-40.org.
jivesoftware.com. 2 NS ns-1774.awsdns-29.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0