Re: about the coexistance scenarios in draft-ietf-v6ops-nat64-pb-statement-req-01

[Iljitsch van Beijnum <[e-mail]>]

On 25 jul 2008, at 15:48, marcelo bagnulo braun wrote:

>  o  a dual stack system connected to a IPv6 domain that is connecting
>     to an IPv4 system.

Point of terminology:

Could we please all agree on what "dual stack" means?

The way I've always used the term is "a system that has both IPv4 and  
IPv6 connectivity, which is global in nature unless explicitly stated  
that it's only local or site-local". However, the above seems to use  
it in the sense "a system that is capable of using both IPv4 and IPv6".

The set of systems conforming to the former definition is obviously a  
subset of those conforming to the latter.

I contend that in 99% of all our discussions, it's useless to make the  
distinction between systems that have certain reachability for  
operational reasons and systems that have certain reachability because  
they don't support both IP versions. Using my definition of "dual  
stack" avoid wasting time in that 99% of cases.

Note also that the use case cited above is based on an unstated  
assumption, which is that if a host supports the second definition of  
dual stack, it must therefore be connected to the IPv4 internet.

The situation we want to reach is where hosts can have just IPv6  
connectivity and still be fully functional.