Apex domains cannot have CNAME records.
Question and response
Question
dig KOLO.NET. NS
Answer
KOLO.NET. 1 NS puck.nether.NET.
KOLO.NET. 1 NS ns-he.KOLO.NET.
KOLO.NET. 1 NS ns.KOLO.NET.
KOLO.NET. 1 NS ans1.nd.KOLO.NET.
KOLO.NET. 1 NS dns44.cloudns.NET.
KOLO.NET. 1 NS dns42.cloudns.NET.
Authority
The response has no authority records.
Additional
ns.kolo.net. 1 A 216.218.215.20
ans1.nd.kolo.net. 1 A 74.123.227.136
puck.nether.NET. 1 A 204.42.254.5
ns-he.kolo.net. 1 A 216.218.215.2
puck.nether.NET. 1 AAAA 2602:fe55:5:0:0:0:0:5
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0