nnu.DNSNODE.NET has no CNAME records.
Question and response
Question
dig nnu.DNSNODE.NET. NS
Answer
The response has no answer records.
Authority
DNSNODE.NET. 3461 SOA nna.netnod.se. noc.netnod.se. 1771459274 7200 1800 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0