To bring your own IPs, you must go through the onboarding process. Work with your account team to understand everything you need to ensure a smooth transition.
Cloudflare requires a service-specific configuration for your prefixes, as well as some requirements common to all BYOIP customers regardless of service type. These requirements are common to all products compatible with BYOIP, such as Magic Transit, CDN, and Spectrum.
There are two major prerequisites before Cloudflare can begin onboarding your IP space.
Optionally, if you use the RPKI protocol to sign your routes, Cloudflare can help with this as well. Just let your account team know if you’re interested in using RPKI.