Subject: [6lo] Generation of IPv6 IIDs

From: Fernando Gont <[email-masked]>
Date: Wed, 30 Apr 2014 22:42:21 -0300

Folks,

We recently contacted the 6lo chairs asking whether there were any
6lo-related documents that should be mentioned in the "Updates" of our
I-D: <http://tools.ietf.org/html/draft-ietf-6man-default-iids>.

We briefly discussed this off-list, and they suggested that raised this
on this list.

Here's the summary of our exchange:

Samita and Ulrich kindly noted that at least some 6lo document does IPv6
address compression on the assumption that the IID contains the
underlying hardware address.

On the other hand we noted that:

* Some OSes (notably Microsoft Windows) have moved away from embedding
MAC addresses in the IIDs (to mitigate the issues discussed in
<http://tools.ietf.org/html/draft-ietf-6man-ipv6-address-generation-privacy>).

* Additionally, there's an existing 6man recommendation (in RFC 7136)
against expecting any semantics in the IPv6 IIDs -- the IID should be
treated as a string of opaque bits.

Dave Thaler had already posted some related comments on this list that
are related to this issue. Please see:

* <http://www.ietf.org/mail-archive/web/6lo/current/msg00403.html>

As noted by Dave (and also by myself), there seem to be some statements
in 6lo documents which seem to go against some 6man recommendations.
That said, in the specific case of header compression, you might have a
case to go against the "SHOULD NOT" in
<http://tools.ietf.org/html/draft-ietf-6man-default-iids> -- although
expecting specific semantics in the IPv6 IIDs still goes against RFC 7136.

All the above said, we still wonder if there are any 6lo-related
documents we should include in the "Updates" of
draft-ietf-6man-default-iids.

P.S.: I apologize if some of the above comments are not that timely...
but I was not following the 6lo work.

Thanks!

Best regards,
-- 
Fernando Gont
SI6 Networks
e-mail: [email-masked]
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