Real-time validation methods
When you use a real-time validation method, Cloudflare verifies your customer’s hostname when your customers adds their DNS routing record to their authoritative DNS.
Use when
Real-time validation methods put less burden on your customers because it does not require any additional actions.
However, it may cause some downtime since Cloudflare takes a few seconds to iterate over DNS records. This downtime also can increase - due to the increasing validation backoff schedule - if your customer takes additional time to add their DNS routing record.
To minimize this downtime, you can continually send no-change PATCH requests for the specific custom hostname until it validates (which resets the validation backoff schedule).
To avoid any chance of downtime, use a pre-validation method
How to
Real-time validation occurs automatically when your customer adds their DNS routing record.
The exact record depends on your Cloudflare for SaaS setup.
Normal setup (CNAME target)
Most customers will have a CNAME target, which requires their customers to create a CNAME record similar to:
Apex proxying
With apex proxying, SaaS customers need to create an A record for their hostname that points to the IP prefix allocated to the SaaS provider’s account.