reply to whfsdude
Re: 6RD Tunneling Yes, Comcast ended the 6rd trial as is was not the correct path forward -- that is a native IPv6 network.
AT&T has decided to be boneheaded and roll with 6rd as their road to IPv6. So they'll be doing IPv6 deployment TWICE because the idiots don't want to take the time to do it right from the beginning. 6rd *requires* IPv4 for it's transport, and puts your IPv4 address in it's IPv6 prefix, which the entire f'ing world will see. As I've pointed out previously, you can use private addresses within 6rd, but then you're forced to use multiple IPv6 prefixes to create 6rd islands to avoid address collisions.
AT&T has *PLENTY* of IPv4 address space. They only way they could be out of space (or anywhere remotely near out) would be from extreme wasteful mismanagement of their blocks -- which would given ARIN the authority to revoke address blocks (not that they would bother.)