Re: [Roll] Stephen Farrell's Discuss on draft-ietf-roll-applicability-home-building-09: (with DISCUSS and COMMENT)

Stephen Farrell <> Sun, 17 May 2015 10:40 UTC

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From: Stephen Farrell <>
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Subject: Re: [Roll] Stephen Farrell's Discuss on draft-ietf-roll-applicability-home-building-09: (with DISCUSS and COMMENT)
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Hi all, and apologies for the slow response...

On 27/04/15 08:05, peter van der Stok wrote:
> Dear all,
> This new draft includes the return to the RFC2119 text.
> It includes all comments answered during the security evaluation.
> It includes suggestions by Michael to answer the DISCUSS raised by
> Stephen Farrell.

I'm sorry to say I don't think we're there yet. I just read the
current draft and I think we still have significant issues for

- If the way in which we are achieving interoperable security is
via layer2-only then I would argue that that has to be more clearly
stated up front (for truth-in-advertising reasons) as otherwise
people may implement/deploy assuming the opposite.

- I really seriously question the proposition that layer2-only
security is sufficient for more complex building requirements.
If that is true, then this document needs to say when it is safe
and when it is unsafe to use RPL in such networks. (I can accept
that layer2-only is ok for simple buildings and homes, at least
for the next few years.)

- The "MUST be present" at the start of 4.1.8 is not quite right.
If the plan here is layer2-only then you need to say something
more like that all RPL packets MUST be sent using the layer2
mechanisms and MUST be verified as having been received using
the layer2 mechanisms. That (I guess) could require some code
if a node can ever emit/receive an insecure message.

- 7.1 remains a collection of references that will not IMO give
us interop when multiple vendors are involved. Can you explain
to me why I'm wrong? (And I don't mean the multicast bit, but
the stuff about unicast.)

Again, apologies for being a barrier to progress here, but I
guess we're paying the price now for us collectively not having
addressed this issue back at the start of the ROLL WG's work. I
do think though that we need to ensure that we don't send out a
set of specifications that might put quite a number of networks
at risk because of our omissions, even if that means we need to
address some technically and politically tricky issues.


PS: Sorry to say I'll be travelling for the next few days so
responses will continue to be slow. Maybe we should try setup a
concall on this in a week or so? If that helps, I'm very happy
to do that.

> It maintains some of the text on the aspects of security in buildings
> that need additional work.
> Greetings,
> Peter
> A New Internet-Draft is available from the on-line Internet-Drafts
> directories.
>  This draft is a work item of the Routing Over Low power and Lossy
> networks Working Group of the IETF.
>         Title           : Applicability Statement: The use of the RPL
> protocol suite in Home Automation and Building Control
>         Authors         : Anders Brandt
>                           Emmanuel Baccelli
>                           Robert Cragie
>                           Peter van der Stok
>     Filename        : draft-ietf-roll-applicability-home-building-10.txt
>     Pages           : 32
>     Date            : 2015-04-26
> 2
> Abstract:
>    The purpose of this document is to provide guidance in the selection
>    and use of protocols from the RPL protocol suite to implement the
>    features required for control in building and home environments.
> The IETF datatracker status page for this draft is:
> There's also a htmlized version available at:
> A diff from the previous version is available at:
> Please note that it may take a couple of minutes from the time of
> submission
> until the htmlized version and diff are available at
> Internet-Drafts are also available by anonymous FTP at:
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