monitor.alt255.nl has no CNAME records.
Question and response
Question
dig monitor.alt255.nl. NS
Answer
The response has no answer records.
Authority
alt255.nl. 2009 SOA ns1.alt255.nl. support.isp-services.nl. 2026012805 14400 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0