Re: [Roll] Erik Kline's Discuss on draft-ietf-roll-useofrplinfo-42: (with DISCUSS and COMMENT)

Erik Kline <> Wed, 16 December 2020 21:26 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 28E963A10E6 for <>; Wed, 16 Dec 2020 13:26:39 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.097
X-Spam-Status: No, score=-2.097 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 8mb83qA6Pzfb for <>; Wed, 16 Dec 2020 13:26:37 -0800 (PST)
Received: from ( [IPv6:2607:f8b0:4864:20::c30]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 02B313A10E4 for <>; Wed, 16 Dec 2020 13:26:36 -0800 (PST)
Received: by with SMTP id q6so5381024ooo.8 for <>; Wed, 16 Dec 2020 13:26:36 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=omNDHEWBkvmi5nrJLi6nN0Nyh5Appfs/kcO/XM8ud0w=; b=BfaE9d1Hmh48+/i76ZGzvC4UCQK7cguBD9PXJGejP270QNcnoR48jgXx2b5Jte7QlU Z8+/NIKrm8eBTZnExDpBU3kSeQ/C9XuxnarkVXVR4FFbuzmyTIvQd+VQW8AuP5AYDlqW 7om/qYYRDzjPtQGRipvE4pfdfivArqkPp89TmwTdp6C3XmRR3HabeiFo9a1dLBA21P5d ud9qw3NLFmRNn1nED1LIPm9sgIiQEXTApc1//gHs8cXZ/wXDmaV48WDOeCpfdNVIDEsX ye2VYhZCjWU5VK1Tf9Goc9kDS9WfOJ5i4wrSyMlxf+RWWBT/kBACqPY8HcRlQK2H82xK UVHg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=omNDHEWBkvmi5nrJLi6nN0Nyh5Appfs/kcO/XM8ud0w=; b=SOQyWTJBKmidiGNkhXDKiOIvcgagqLJ7bieWjUy1eteM4ySy4Moh61JWwF0DcL8w/w vL2EFNFz9T0wLK9iV6i+CFdcOvqpc9vfwwFifpf8gQ5bda+omXDwz1K92I2mOouaoT25 0Ck57IPtZPtUnZkmdLdPwoppfW98z4CkBsor1dcpLBpJIVw3cXZYsStstSl8+Rtz/G+2 XIDSxkO2M1m94cS/2Go1d+ks491XJi+mSOGNDZBOPfoBKze9El/VhQC4ORFyU8NZweoE eB/46oCTdGIwD6mmsbBLfTOC6KLZD+jjs1BYmlQxrKkNrFEmHBg6REyljJu9c9Lw5arn 0K+g==
X-Gm-Message-State: AOAM53105IqqwfYIdXRteEfepwm4u74lsYRVN52U3TvCNI8AR34ys+7s I29k4/60kg/lXQel9t6BA5lvR6FEjNDbGOd2zDY=
X-Google-Smtp-Source: ABdhPJyCEe112FqkJ0QZfp1elrqB6M+Fo5dN0qSKWB9XyB9knGrlJ+7DzehLqcdA6Dki/67hw60IcpwJpTz+89YLKn8=
X-Received: by 2002:a4a:94e2:: with SMTP id l31mr11502784ooi.66.1608153996164; Wed, 16 Dec 2020 13:26:36 -0800 (PST)
MIME-Version: 1.0
References: <> <9337.1608141694@localhost>
In-Reply-To: <9337.1608141694@localhost>
From: Erik Kline <>
Date: Wed, 16 Dec 2020 13:26:25 -0800
Message-ID: <>
To: Michael Richardson <>
Cc: Routing Over Low power and Lossy networks <>
Content-Type: multipart/alternative; boundary="000000000000af821a05b69b87cd"
Archived-At: <>
Subject: Re: [Roll] Erik Kline's Discuss on draft-ietf-roll-useofrplinfo-42: (with DISCUSS and COMMENT)
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Routing Over Low power and Lossy networks <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Wed, 16 Dec 2020 21:26:39 -0000

On Wed, Dec 16, 2020 at 10:01 AM Michael Richardson <>

> Erik Kline via Datatracker <> wrote:
>     >   I might recommend instead referring to RFC 6554 S4.2 for how to
>     > handle RH3's if the node is also a RPL-aware router and say it MUST
>     > drop the packet if segments left is non-zero and it's not a RPL-aware
>     > router.
>     >   Related: I'd also recommend:
>     >   "It should just be noted that an incoming RH3 must be fully
> consumed,
>     > or very carefully inspected."
>     ->
>     >   "It should just be noted that an incoming RH3 MUST be fully
>     > consumed."
> I think that Pascal and I, when we write the "carefully inspected", is
> that we are imagining situations where the topology is a bit subtle.
> Perhaps there are firewalls involved.
> Perhaps a device has multiple interfaces (many radios for instance) and the
> extra segments address the other interfaces.
> Also draft-ietf-anima-autonomic-control-plane uses storing mode, so never
> has
> RH3 headers, but imagine if it did.
> One could have a situation where the physical system containing one or more
> layers of container was not the ultimate last hop from a logical point of
> view.  Rather than inner container was.  So, it's all the same stack
> actually.  In that case, an optimization might be to process more than
> one segment in that stack.
> (The ANIMA ACP definitely supports having VMs and containers inside
> routers)

(trying to respond to both threads)

I guess, one way to look at it would be: for any given node, receiving a
packet with an RH3 and segments left > 0, does the discussion here change
anything?  If the node is part of nested layers of networking it might do
what it's configured to do, and if it's a plain vanilla host it should
reject the packet.

If there's no behaviour change then perhaps we can just trim all the text
and point text elsewhre (I have a note from reading last night about
roll-unaware-leaves S5.4 being a possible landing spot for a pointer, as
Pascal mentioned above).

Thanks for the ongoing discussion!

So, I can live with your suggestion, because in my case above,
> we can argue that it's still "consumed"
>     > * I'm confused by the use of "consumed" here.  Is the final RH3 entry
>     > RUL's address?  I guess you could say RH penultimate hop "consumes"
> the
>     > header because the ultimate destination address is put in the header
> DA
>     > field.  Seems a bit odd though.
> Yes, that's what we mean.
> Once that ultimate destination is in the DA, then the RH3 is a dummy, but
> one
> we are aren't supposed to remove.
>     >   I assume 6LR_n gets RUL's address from the last segment in RH3.
>     >   "Consumed" means segments left == 0, I guess?  I suppose should
> have
>     > picked up on this terminology when it was first used in Section 2.
>     > Maybe clarify what it means in that section (2)?
> Yes.
> --
> Michael Richardson <>   . o O ( IPv6 IøT consulting )
>            Sandelman Software Works Inc, Ottawa and Worldwide