Re: [Softwires] WG last call on draft-ietf-softwire-public-4over6-01

[Peng Wu <[e-mail]>]

Woj,

On Mon, Jun 11, 2012 at 5:10 PM, Wojciech Dec <[e-mail]> wrote:
> There is basic question regarding this draft, one that has also been raised
> at previous WG meetings: "why is it needed?".
It's actually written in section 4 of the draft.

> There is a deeper issue here: This draft seems to give the impression that
> running such a regular public addressed DHCPv4 based overlay on IPv6 is a
> simple idea, as opposed to native dual stack. It is anything but, given that
Why is it opposed to native dual-stack? It's IPv4-over-IPv6, similar
to scenario of DS-Lite and MAP/4rd.
I thought the assumption of IPv4-over-IPv6 is that you cannot/do not
want to provision native dual-stack?

> a) it it requires changes to DHCPv4 processing b) it introduces non trivial
> dependencies between DHCPv6 and DHCPv4 and tunnelling c) requires changes to
> CPE d) makes life really a mess if we consider a real dual stack CPE.
a) Simply make DHCPv4 work with IPv6 as underlying transport. No
essential changes to protocol processing.
b) What really matters here is provisioning the IPv4 address through
DHCPv4. Just like in MAP/4rd, you provision the address through
DHCPv6.
In pb4over6 DHCPv6 is only an *option* to provide the concentrator
address. You have similar logic too in MAP.
So I don't think it's "non trivial dependancy". They are similar
functions for all IPv4-over-IPv6 mechanisms that need provisioning,
only different technical paths.
c) Any IPv4-over-IPv6 mechanism requires change to CPE