Subject: Do you pass the real webhosting IP to search engines?
Thank you for contacting CloudFlare.
We have registered our IPs with Google and Bing as a CDN provider to prevent a negative impact to your page rank. Major crawlers do not penalize for IP changes if they are from a CDN since those IPs change very frequently.
No, we do not pass the source IP of your origin server to crawlers. There is no standardized way to do so. Crawlers only know the IP that your domain resolves to, which would be CloudFlare IPs if the service is active.
Let us know if you have any other questions.”