Adhering to modern web protocols, Cloudflare is transitioning customers under every plan to IPv6. Read why Cloudflare found this was an important feature for every customer to have access to in: Supporting the Transition to IPv6 only. Now clients with IPv6 connections only will be able to access on IPv4 or IPv6 enabled sites through our IPv6 Gateway with no additional configuration or hardware.
What if I don't want my site running on IPv6?
For customers that do not wish to make this transition, Cloudflare has enabled the option to toggle IPv6 on or off.
In the case that a client connects via IPv6 but the site is using an obsolete server software that accepts origin visitor IP addresses in IPv4 only, we have created Pseudo IPv4. This feature will create a IPv4 address to represent the visitor's IPv6 address in the headers. The header
Cf-Pseudo-IPv4 will be added to the request. The following headers will be rewritten in the new IPv4 address:
X-Forwarded-ForVisitors can still connect over IPv6 and servers can still interpret an IPv4 client address.