ARIN-PPML Message

[arin-ppml] Draft Policy 2011-5: Shared Transition Space for IPv4 Address Extension - IAB comment

On Jun 28, 2011, at 5:50 AM, Jimmy Hess wrote:

> On Tue, Jun 28, 2011 at 1:43 AM, Joel Jaeggli <joelja at bogus.com> wrote:
>> On Jun 27, 2011, at 11:24 PM, Benson Schliesser wrote:
>>> On Jun 28, 2011, at 0:25, David Kessens <david.kessens at nsn.com> wrote:
>> It's new private scope v4 address space carved out of ipv4 unicast space. by definition it breaks assumptions that existing hosts and applications make about non-rfc-1918 space.
>> 
> [snip]
> 
> What assumptions would those be?

That a port mapped to a the outside of a cpe which does not have an rfc 1918 address will in fact be reachable (example by upnp or nat pmp)

That an ipv4 unicast address can be used as source or destination for an auto-tunneling mechanism. 

Aa specific example of the later with an rfc-1918 address assignment an existing implmentation of 6to4 will simply fail, which is the desired behavior, in the case of a private scope address carved out of a new range it will assign itself a /64 and proceed to fire ipv6 traffic into a blackhole. existing 6to4 cpe cause enough breakage as it is without compounding it.

> The word 'private scope'  doesn't appear anywhere in the proposal.

If you can't advertise it into the dfz what other scope does it have?

you can see all this of course in the minutes when the proposal was discussed in v6ops.

http://www.ietf.org/proceedings/79/minutes/v6ops.txt