Re: [6tisch] Roman Danyliw's Discuss on draft-ietf-6tisch-enrollment-enhanced-beacon-12: (with DISCUSS and COMMENT)

Michael Richardson <> Mon, 24 February 2020 23:24 UTC

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From: Michael Richardson <>
To: Roman Danyliw <>
cc: The IESG <>, "pthubert\" <>, "6tisch-chairs\" <>, "6tisch\" <>, "draft-ietf-6tisch-enrollment-enhanced-beacon\" <>
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Date: Mon, 24 Feb 2020 18:23:59 -0500
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Subject: Re: [6tisch] Roman Danyliw's Discuss on draft-ietf-6tisch-enrollment-enhanced-beacon-12: (with DISCUSS and COMMENT)
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Roman Danyliw <> wrote:
    >> > ** Section 2.  network id.  Can you please clarify the computation of
    >> > the default value using SHA-256.
    >> I have changed the text to say:
    >> : In a 6tisch network, where RPL {{RFC6550}} is used as the mesh routing
    >> protocol, the
    >> network ID can be constructed from a truncated SHA256 hash of the prefix
    >> (/64) of the
    >> network.  This will be done by the RPL DODAG root and communicated by
    >> the RPL
    >> Configuration Option payloads, so it is not calculated more than once.
    >> That is just a suggestion for a default algorithm: it may be set in any
    >> convenience way that results in a non-identifing value.

    > Understood.  However, to clarify, is there guidance on how this
    > truncation should be applied (i.e., which bits are supposed to be used?
    > )?

The calculation is
a) a suggestion on how the control plane should initialize itself by default.
b) done once in the 6LBR, so any truncation is acceptable.

I.e. it doesn't matter how it's done.

Communicating the NetworkID down the RPL DODAG is ROLL WG work, which has not
proceeded in pace with this work.

Michael Richardson <>ca>, Sandelman Software Works
 -= IPv6 IoT consulting =-