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

[Lorenzo Colitti <[e-mail]>]

On Thu, Jan 12, 2017 at 6:21 PM, Fernando Gont <[e-mail]>
wrote:

> > 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.
>
> If you use temp-only, that means the inability to have e.g. long-lived
> SSH sessions. I don't think that's the current operating "model", even
> less for IPv6.
>

I don't see why we should forbid this. It's a legitimate implementation
choice, and has excellent privacy properties :-)


> So far, the only two standardized algorithms for generating IIDs with
> SLAAC are RFC7217, RFC4941, and traditional slaac (modified eui-64).
> Clearly, you can hack your code and commit it. Being that this is
> standardization body, I would expect that we're agree on standardizing
> reasonable approaches, and calling bad approaches as such.
>

Sure. If you can find rough consensus to say all other methods of
generating IIDs are bad and should not be used, the IETF will publish a
document saying that. My bet is that you won't.

To get back to the original point: in the current state of the documents
that we have published or are about to publish (e.g., the default-iids
draft), as reflecting the consensus call sin th it's not true that modified
EUI-64 is not recommended. It's only not recommended if you use stable
link-layer addresses.

Bob, Ole, Suresh: can we also amend or remove this text in 4291bis before
we publish it? I think it's an oversight because there was clear consensus
in 6man (Fernando being in the rough) that it was OK to use modified EUI-64
with non-stable MAC addresses:

   Earlier versions of this document described a method of forming
   interface identifiers derived from IEEE MAC-layer addresses call
   Modified EUI-64 format.  These are described in Appendix A and are no
   longer recommended.