php52.agn.cyso.net has no CNAME records.
Question and response
Question
dig php52.agn.cyso.net. NS
Answer
The response has no answer records.
Authority
agn.cyso.net. 300 SOA ns1.cyso.nl. dnsadmin.cysonet.com. 1771459200 16384 2048 1048576 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0