Apex domains cannot have CNAME records.
Question and response
Question
dig rocks. NS
Answer
rocks. 5 NS v2n0.nic.rocks.
rocks. 5 NS v0n3.nic.rocks.
rocks. 5 NS v0n0.nic.rocks.
rocks. 5 NS v0n2.nic.rocks.
rocks. 5 NS v0n1.nic.rocks.
rocks. 5 NS v2n1.nic.rocks.
Authority
The response has no authority records.
Additional
v0n0.nic.rocks. 144724 A 65.22.32.35
v0n1.nic.rocks. 144724 A 65.22.33.35
v0n2.nic.rocks. 144724 A 65.22.34.35
v0n3.nic.rocks. 144724 A 161.232.16.35
v2n0.nic.rocks. 144724 A 65.22.35.35
v2n1.nic.rocks. 144724 A 161.232.17.35
v0n0.nic.rocks. 144724 AAAA 2a01:8840:22:0:0:0:0:35
v0n1.nic.rocks. 144724 AAAA 2a01:8840:23:0:0:0:0:35
v0n2.nic.rocks. 144724 AAAA 2a01:8840:24:0:0:0:0:35
v0n3.nic.rocks. 144724 AAAA 2a01:8840:fa:0:0:0:0:35
v2n0.nic.rocks. 144724 AAAA 2a01:8840:25:0:0:0:0:35
v2n1.nic.rocks. 144724 AAAA 2a01:8840:fb:0:0:0:0:35
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0