Ha, I guess this is one way of summarizing it :) Author here. I wanted to share more subtleties of the design, but maybe I failed.
Indeed, the starting point is sharing IP's across servers with port-ranges.
But there is more:
* awesome performance allowed by anycast.
* ability to route /32 instead of /24 per datacenter.
Generally, with this tech we can have much better IP usage density, without sacrificing reliability or performance. You can call it "global anycast-based stateless NAT" but that often implies some magic router configuration, which we don't have.
Here's one example of problems we run into - the lack of connectx() syscall on Linux - makes it hard to actually select port range to originate connections from:
Indeed, the starting point is sharing IP's across servers with port-ranges.
But there is more:
* awesome performance allowed by anycast.
* ability to route /32 instead of /24 per datacenter.
Generally, with this tech we can have much better IP usage density, without sacrificing reliability or performance. You can call it "global anycast-based stateless NAT" but that often implies some magic router configuration, which we don't have.
Here's one example of problems we run into - the lack of connectx() syscall on Linux - makes it hard to actually select port range to originate connections from:
https://blog.cloudflare.com/how-to-stop-running-out-of-ephem...