Apex domains cannot have CNAME records.
Question and response
Question
dig ip.campus-rv.net. NS
Answer
ip.campus-rv.net. 5 NS ns2.campus-rv.net.
ip.campus-rv.net. 5 NS ns.campus-rv.net.
Authority
The response has no authority records.
Additional
ns.campus-rv.net. 5 A 193.106.144.10
ns2.campus-rv.net. 5 A 51.195.254.54
ns.campus-rv.net. 5 AAAA 2a00:fc00:e000:0:0:0:0:53
ns2.campus-rv.net. 5 AAAA 2001:41d0:801:2000:0:0:0:50a0
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0