Philip Homburg wrote:
It should be clear that an IPv4-only host only speaks IPv4. This means that communication with an IPv4-only host has to be IPv4.
This did not have to be true, had there been an extension/option standardized at the same time as IPv6 for IPv4 packets to be gateway'd into IPv6 transparently and efficiently (thru any dual stacked host/router), than at this point we would have likely been looking at 4 classes of nodes - IPv4 only, legacy, requires translation to communicate directly with ipv6 - IPv4 only, extended, just needs a gateway to communicate directly with IPv6 - Dual Stack - IPv6 only Such additional functionality, could have been organically updated into most major OS's without any required network topology changes. Joe