grdns.ics.forth.gr has no CNAME records.
Question and response
Question
dig grdns.ics.forth.gr. NS
Answer
The response has no answer records.
Authority
ics.forth.gr. 7089 SOA dns1.ics.forth.gr. noc.ics.forth.gr. 1771888201 3600 7200 1209600 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0