What led me to that conclusion was that I checked a few of the IPs and they seem to be assigned by hosting providers to several websites (other than the one being pointed as the culprit), for example
Hi Sandro,
Sorry for my late reply. Apparantly I’m only allowed so much replies within so many hours.
I implemented your advice with the .0/24. I looks like I blocked it, but my guess is because I blocked kixtart.nl with is there technical contact person/ hostingprovider.
Thanks to the url of floripare I found the ip adress for eerste.nameserver.nl where w3 howards home leads to.