Re: [v6ops] New Version Notification for draft-palet-v6ops-ipv6-only-02.txt

[Fred Baker <[e-mail]>]

> On Oct 17, 2017, at 10:43 AM, JORDI PALET MARTINEZ <[e-mail]> wrote:
> 
>    - I think a short "Definition of IPv4-only" would be useful to include.

A little rumination in context. Hats off.

To me, an IPv4-only thing is a thing that can only communicate using IPv4. That would be true of an IPv4-only host, an IPv4-only LAN, or an IPv4-only network. In each case, there is a question of perspective: if an ISP only offers a subscriber IPv4 addresses or prefixes, then the subscriber is IPv4-only from the ISP's perspective, even though it might be using something else internally or when communicating via some other connectivity. If we are speaking from the perspective of the host itself, it might mean that it is perfectly capable of communicating using something else, but it has only been provisioned with an IPv4 address, or it can communicate with peers on its LAN using something else, but the router is IPv4-only, and so when it communicates with devices beyond the router (or they try to communicate with it), IPv4 is the only thing that works.

So, suggested text:

IPv4-only: only capable of or provisioned to communicate using IPv4. The description is always from a perspective, whether the perspective of a host or network seeking to communicate, or that of another host or network describing a communication peer.