Why is this your IP? It will simply be an address which your host also assigned to you.
It would seem as if that address is properly configured to redirect to the naked domain, which suggests that it was (possibly still is) used for the domain in question.
Why should I discuss it with my host?
I see it as MY ip because it is assigned to MY server. The IP is shared between 5 of MY domains. How can it be that cloudflare dont bother about what ip subdomains are pointed at in the cloudflare dns. Does it mean that I can point my domains to any IP? If so its high time to leave cloudflare. I have no time to block new subdomains every hour of the day
that is what I try to find out. Someone register subdomain and point them to that IP. The host mean its not a datacenter problem
But to stop it I will add an IP, proxy it with Cloudflare and see if it stops. As I understand it there should not be any possibility to find out the real IP of my server
That’s something you need to check on your server, Cloudflare is not involved here.
That can always happen is nothing “illegal” either. Just make sure your server does not respond for that domain respectively returns an appropriate error message when a request for it comes in.
You could also restrict requests only to Cloudflare addresses and enable Cloudflare’s client certificate authentication (Origin Pulls). That would guarantee that only Cloudflare can connect.