- The common thinking for the last 10+ years has been to say that dual stack was the answer to IPv6 transition and that most things would be converted to dual stack way before we ran out of IPv4. Well, it has not happened. We are going to run out of IPv4 addresses soon, way before any significant IPv6 deployment will have occured. However, the quasi totality of the Internet and most of the computers in the home are still IPv4-only. Several distributed NAT architectures, based on different possible flavors of a carrier-grade NAT, are Durand Expires August 27, 2008 [Page 1] Internet-Draft Abbreviated Title February 2008 presented as solutions to maintain some form of connectivity between those home environments and the legacy Internet.