Apex domains cannot have CNAME records.
Question and response
Question
dig 123.net. NS
Answer
123.net. 5 NS ns1.123net.us.
123.net. 5 NS ns3.distance.net.
123.net. 5 NS ns2.distance.net.
123.net. 5 NS ns4.123net.us.
Authority
The response has no authority records.
Additional
ns1.123net.us. 5 A 137.117.101.85
ns2.distance.net. 5 A 69.39.68.50
ns3.distance.net. 5 A 209.124.48.178
ns4.123net.us. 5 A 3.128.42.46
ns1.123net.us. 5 AAAA 2a01:111:f100:2000:0:0:a83e:332b
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0