grid01.geant.net has no CNAME records.
Question and response
Question
dig grid01.geant.net. NS
Answer
The response has no answer records.
Authority
geant.net. 735 SOA grid01.geant.net. hostmaster.dante.net. 2015081010 3600 7200 2419200 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0