Historically, we have rarely talked about how our servers fetch
the content from the Internet. In this blog we’re going to cover
this gap. We’ll discuss how we manage Cloudflare IP addresses
used to retrieve the data from the Internet, how our egress
network design has evolved, how we optimized it for best use
of available IP space and introduce our soft-anycast technology.
— Read on blog.cloudflare.com/cloudflare-servers-dont-own-ips-anymore/