I wasn't implying it was IPv4 only, I was merely teasingly repeating rumors that a lot of low level infrastructure still has IPv4 assumptions that Amazon has had enough IPv4 addresses to date that they don't need fix those underlying assumptions in their data centers. It's mostly dumb rumor mongering, I suppose, as I'm not sure I have a citation for that off hand other than other HN jabs at Amazon/AWS. I'm sorry for that, it was an unnecessary jab/tease, that I will blame on pre-coffee brain.

They used to -- that's why IPv6 was so slow to arrive. But that's fixed now except possibly in some parts of "legacy EC2".

We have IPv4 and IPv6 public interfaces on our AWS services.