someone is using Cloudflare to point directly to my server. My webserver is not delivering any content in case that the hostnames do not match, but the real issue here is that am receiving thousands or requests that going undetected.
so all the requests i receive are under Cloudflare IPs
A possible option would be by switching your own sites to run over a Cloudflare Tunnel.
That way, you would NOT have to open any ports, or have any IP addresses added to the inbound policies of your firewall, as the Cloudflare Tunnel would connect outbound towards the Cloudflare network.
Since it sounds like that your server’s IP address(es) have already been exposed, you won’t really be able to prevent the “attempted” traffic from happening, however, if your hosting provider allows you to, you can eventually rotate the IP address(es) after having re-configured your set up to run through a Cloudflare Tunnel.
Setting the assigned nameservers at the registrar is proves domain ownership, or an equivalent level of control.
It sounds like you want an HTTP challenge to be verified by the origin server. That is an interesting idea. It might be worth posting that in #feedback:feature-request
Thanks for the reply!
My apologies, yes i meant to say proof of server ownership.
In this scenario if Cloudflare requires me to proof that i own the server i pointed my domain to using clouflare dns.
Then in the above case i would only had to allowlist Cloudflare IPs and block anything else. So in this way the attacker will not be able to use Cloudflare to point to my server directly and every request should pass from my Cloudflare configurations and from there can be detected/filtered/blocked.