Re: [homenet] Let's make in-home ULA presence a MUST !?

[Markus Stenberg <[e-mail]>]

On 22.10.2014, at 20.51, James Woodyatt <[e-mail]> wrote:
> On Wed, Oct 22, 2014 at 12:19 AM, Markus Stenberg <[e-mail]> wrote:
> Wait. Where did this "and should not be routable anywhere outside" recommendation come from? And if it's only a recommendation and not a requirement, then it still matters, right? I don't see that we can meaningfully make it a requirement, and I would advise against attempting to make it a recommendation. I don’t believe such a recommendation will be followed.

I was not writing anything based on recommendations ; I just wrote taxonomy of different ULA cases that I currently see as realistic, and in the [3], there does not seem to be any (automated) reason for routing outside the administrative domain that is the HNCP router network-

RFC4193 abstract.

   This document defines an IPv6 unicast address format that is globally
   unique and is intended for local communications, usually inside of a
   site.  These addresses are not expected to be routable on the global
   Internet.

If you are doing ‘private routing’ or whatever, note the categories [1] and [2] I defined that _are_ routable and should work for that fine.

I am just interested in the case [3]. For it, specifying just some fixed /48 or something for HNCP administrative scope use would be fine too. If multiple HNCP-using networks want to communicate, they may share the prefix (or at least make sure the /64s allocated are unique so the communication works between all routed links). 

The idea that they share (partially?) routes but not HNCP state sounds strange to me, but even for that, the [1]/[2] sub-delegation options should work fine.

Cheers,

-Markus