Re: IPv6-only devices?

[Ronald van der Pol <Ronald.vanderPol@rvdp.org>]

On Thu, Feb 06, 2003 at 16:16:09 -0500, Keith Moore wrote:

> What I'm pointing out is that trying to make every application speak
> both IPv4 and IPv6 is a waste of energy.

I don't agree. Dual stack enables a smooth migration from v4 to v6,
but see below.

> It's not even possible
> in general, and for many applications there are going to be inherent
> biases toward either v4 or v6 - e.g. for backward compatibility
> reasons, because the application inherently requires a large flat global
> address space, or because the application was initially deployed in
> portions of the network (e.g. the cell phone newtork, or certain parts
> of the world) that were more friendly to v6 than to v4.

If you read my initial email again you would see that I also say that
it is perfectly OK to have IPv6-only appliances that do not need to
communicate to IPv4-only nodes.

I think dual stack is the best migration path. I also think that the
transition period should be short. Not a flag day, but also not a
transition period of decades. I agree with you that running dual
stack networks is costly *). I think the transition should be done
in a few years. I think this means the IETF should restrict new
work to IPv6-only. In other words: either move to IPv6 or abondon
the effort.

*) Dual stack is costly. ISPs have to maintain 2 number plans, 2 ACL
lists, etc. In case of problems ISPs need to figure out if it is an
IPv4-only problem, an IPv6-only problem or a problem of both stacks.
Vendors need to track IPv6-only bugs, IPv4-only bug and bugs that
exist in both protocols. When vendors introduce a new feature,
customers have to ask if the feature is supported in IPv4, in IPv6
or in both. Etcetera, etcetera.

	rvdp