Re: <draft-ietf-6man-default-iids> update to rfc2464bis

[Lorenzo Colitti <[e-mail]>]

On Thu, Jan 12, 2017 at 4:20 PM, Fernando Gont <[e-mail]>
wrote:

> > We do
> > recommended that nodes use RFC7217 addresses by default, but only if the
> > node wishes to create stable addresses, and there is no requirement that
> > a node do so.
>
> So far, the current specs essentially require that. RFC4941 (the only
> spec we have for non-temporary addresses) require that the be generated
> along with the traditional (stable) addresses.
>

I don't see what RFC 4941 has to do with this discussion. RFC4941 is a
method of generating temporary addresses. It is not required to be used,
and it is not the only way of forming IP addresses that can change over
time.

FWIW, I do think there are scenarios in which you might want to do
> temporary-only, but we certainly need an update to the current specs in
> that regard (and guidance regarding where to use each).
>

There are lots of ways of forming interface identifiers. We should
absolutely not rule out the ability to form IIDs from non-stable MAC
addresses (IIRC the text in default-iids was carefully modified to ensure
that that would still be possible, based on substantial discussions in the
WG), and we should *absolutely* not say that the only possible form of
interface identifiers on an Ethernet interface are RFC7217 and RFC4941.


> That aside, in the context of temp-only addresses, doing Modified-EUI64
> based on a randomized MAC address is still a bad idea:
>

I am not going to rehash that argument here. Everything we had to say about
that is in the archives.