Apex domains cannot have CNAME records.
Question and response
Question
dig iphh.net. NS
Answer
iphh.net. 1 NS ns2.iphh.de.
iphh.net. 1 NS ns1.iphh.de.
iphh.net. 1 NS ns3.iphh.net.
Authority
The response has no authority records.
Additional
ns1.iphh.de. 1 A 213.128.128.33
ns2.iphh.de. 1 A 213.128.129.66
ns3.iphh.net. 1 A 212.12.42.2
ns1.iphh.de. 1 AAAA 2001:868:0:180:0:0:1:1
ns2.iphh.de. 1 AAAA 2001:868:0:181:0:0:0:1
ns3.iphh.net. 1 AAAA 2a00:ea8:31bb:0:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0