ns1.sits.pro has no CNAME records.
Question and response
Question
dig ns1.sits.pro. NS
Answer
The response has no answer records.
Authority
sits.pro. 2263 SOA ns1.sits.pro. sd.sits.nl. 2014071785 10800 3600 1814400 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0