ns2.tut.net has no CNAME records.
Question and response
Question
dig ns2.tut.net. NS
Answer
The response has no answer records.
Authority
tut.net. 2745 SOA ns1.tut.net. noc.tut.net. 2026022000 3600 600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0