ns2.th.seeweb.it has no CNAME records.
Question and response
Question
dig ns2.th.seeweb.it. NS
Answer
The response has no answer records.
Authority
th.seeweb.it. 9715 SOA ns1.th.seeweb.it. hostmaster.seeweb.it. 2014111347 86400 900 4838400 21600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0