Apex domains cannot have CNAME records.
Question and response
Question
dig nic.travel. NS
Answer
nic.travel. 5 NS v2n1.nic.travel.
nic.travel. 5 NS v0n2.nic.travel.
nic.travel. 5 NS v0n0.nic.travel.
nic.travel. 5 NS v0n1.nic.travel.
nic.travel. 5 NS v0n3.nic.travel.
nic.travel. 5 NS v2n0.nic.travel.
Authority
The response has no authority records.
Additional
v0n0.nic.travel. 167327 A 65.22.28.8
v0n1.nic.travel. 167327 A 65.22.29.8
v0n2.nic.travel. 105580 A 65.22.30.8
v0n3.nic.travel. 167327 A 161.232.14.8
v2n0.nic.travel. 105580 A 65.22.31.8
v2n1.nic.travel. 167327 A 161.232.15.8
v0n0.nic.travel. 167327 AAAA 2a01:8840:1e:0:0:0:0:8
v0n1.nic.travel. 167327 AAAA 2a01:8840:1f:0:0:0:0:8
v0n2.nic.travel. 105580 AAAA 2a01:8840:20:0:0:0:0:8
v0n3.nic.travel. 167327 AAAA 2a01:8840:f8:0:0:0:0:8
v2n0.nic.travel. 105580 AAAA 2a01:8840:21:0:0:0:0:8
v2n1.nic.travel. 167327 AAAA 2a01:8840:f9:0:0:0:0:8
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0