Apex domains cannot have CNAME records.
Question and response
Question
dig networklayer.com. NS
Answer
networklayer.com. 4 NS ns1.softlayer.net.
networklayer.com. 4 NS ns2.networklayer.com.
networklayer.com. 4 NS ns2.softlayer.net.
networklayer.com. 4 NS ns1.networklayer.com.
Authority
The response has no authority records.
Additional
ns1.networklayer.com. 4 A 67.228.254.22
ns2.networklayer.com. 4 A 67.228.255.22
ns1.networklayer.com. 4 AAAA 2607:f0d0:0:15:10:0:0:1
ns2.networklayer.com. 4 AAAA 2607:f0d0:0:15:20:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0