It’s easier than you might think, I used to blackhole anything non-Cloudflare and they offer a list of their IP’s: https://www.cloudflare.com/ips/ https://www.

It’s easier than you might think, I used to blackhole anything non-Cloudflare and they offer a list of their IP’s: https://www.cloudflare.com/ips/ https://www.cloudflare.com/ips/