Re: [Cbor] changes in draft-ietf-cbor-network-addresses-05.txt

Brian E Carpenter <brian.e.carpenter@gmail.com> Sun, 01 August 2021 22:56 UTC

Return-Path: <brian.e.carpenter@gmail.com>
X-Original-To: cbor@ietfa.amsl.com
Delivered-To: cbor@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 757BE3A16A6; Sun, 1 Aug 2021 15:56:14 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.099
X-Spam-Level:
X-Spam-Status: No, score=-2.099 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, NICE_REPLY_A=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rn8f5WSjteos; Sun, 1 Aug 2021 15:56:10 -0700 (PDT)
Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id C60FC3A16A5; Sun, 1 Aug 2021 15:56:09 -0700 (PDT)
Received: by mail-pl1-x629.google.com with SMTP id k1so17475470plt.12; Sun, 01 Aug 2021 15:56:09 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=ke8CZhBqbBR1krI38wIExWYjKsNl8zfqFR2Cea0/6Yo=; b=rZ2qq9sFBrx8M42dMV/1fVK+edO3XEL5AC9UXnQKu3Fp9AEwt3a+ePcL/a0NBml4G2 bEDbgc14xRKQhlRsR8p5f9+yXjpCogEJjfD8afPqD7AcrI4jFcUp/60aoii2+rsjaO1S mh1JoKTwF0vwa+LLcDbO78MbSgsjGFSrSoUyHqiI+PERkoc36nBcrz0QmwtbbNjuNxaC GWzv7aKDWxNh0C0nhRH4zpYT4Q8pLYqiDn1KPngP+F1XDuCS5UckQIPLFdJksVcWg7uZ uyaYkF2XbX6uHYY5fWLhSzm5y2cK90E5N86i2nkONaPl5KNSmrLPZZXqOsTOdMxIopjE lDag==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ke8CZhBqbBR1krI38wIExWYjKsNl8zfqFR2Cea0/6Yo=; b=iIDg93sm9+UD99cDVuTwDaq8Fb9cjoFiFLzCiRVn9WJ1EB5p3QnReXstFsGv/bGglU j4GovSz61rZbMfvY3c5de6RqbPy6h9sNupdcrfMub5TFGl045B+cjvO3AN1t68BUgT14 SSPMm/C+mUuxnFmnRDa8NucU+HBbLoH4tpPPVOBfx7hxHb89MAikSqRkKBW90TY9gEVa FZS2J2koAQsP7gQuheoRDsbX40WYQjOpjYFsKNemHoOCT5jruUYKsj22m1MTONvUxv39 9QmnGGAUMclmtIvighQX0yW859RpWgKjK0JFENC2FuI9znkZTiYb0VNUL8ixDwtkhGqK zXbw==
X-Gm-Message-State: AOAM531GkSeg5iyop3tEhb6KIxbHiXQyZ0vZidNkwO+i/BvRF5Nz5wK3 MGhfPtgRgjkATAEucVdge1EY6eHx8myXZA==
X-Google-Smtp-Source: ABdhPJxVo0q/+fk4mqr0uJtD6R85ROOs1gbm7otWR3Ac4XrJwjYhXpaYRNVgcnnxhSAvUqWtS6udNg==
X-Received: by 2002:a65:4244:: with SMTP id d4mr6356916pgq.83.1627858568510; Sun, 01 Aug 2021 15:56:08 -0700 (PDT)
Received: from ?IPv6:2406:e003:1188:5b01:80b2:5c79:2266:e431? ([2406:e003:1188:5b01:80b2:5c79:2266:e431]) by smtp.gmail.com with ESMTPSA id 65sm9548957pgi.12.2021.08.01.15.56.05 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 01 Aug 2021 15:56:07 -0700 (PDT)
To: Michael Richardson <mcr+ietf@sandelman.ca>, Erik Kline <ek.ietf@gmail.com>, "cbor@ietf.org" <cbor@ietf.org>, 6MAN <6man@ietf.org>
References: <162608928922.11086.12172415971165753394@ietfa.amsl.com> <29067.1626090045@localhost> <CAMGpriUnfMjhk7teAN-A0j5SCK=BpyJEDC+NOCJtHzmF1BFeow@mail.gmail.com> <aa9884b5-fd58-60cb-fa1d-b2d76f5a09a1@gmail.com> <VI1PR07MB6256E2C9CC9565FF2F080B5DA0E89@VI1PR07MB6256.eurprd07.prod.outlook.com> <c2c7a576-e138-1364-5ed0-a2987c1c1974@gmail.com> <20210727210706.buavt5nwairrjblf@anna.jacobs.jacobs-university.de> <e889a219-26b2-2a2e-6d05-bb6c7db1f89d@gmail.com> <20210801113001.yksklfouoz6v4hvz@anna.jacobs.jacobs-university.de> <b5f1c62e-4aa4-a397-8777-b3ec0eeafccc@gmail.com> <27179.1627856496@localhost>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Message-ID: <77455e4c-9c90-eed5-b37c-061bc46fc06a@gmail.com>
Date: Mon, 2 Aug 2021 10:56:02 +1200
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0
MIME-Version: 1.0
In-Reply-To: <27179.1627856496@localhost>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://mailarchive.ietf.org/arch/msg/cbor/4vOxRAHk3bDaDh8QMeKS_p1pm8A>
Subject: Re: [Cbor] changes in draft-ietf-cbor-network-addresses-05.txt
X-BeenThere: cbor@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Concise Binary Object Representation \(CBOR\)" <cbor.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/cbor>, <mailto:cbor-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/cbor/>
List-Post: <mailto:cbor@ietf.org>
List-Help: <mailto:cbor-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/cbor>, <mailto:cbor-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 01 Aug 2021 22:56:15 -0000

> For the Interface form, adding a third (optional) field for scope is easy.
> I am open to suggestions for handling the Address format.

It gets a bit messy. If you transmit the zone id as a string, you
could use [address, 'eth0'] which would be distinguishable from the
other cases.

By the way, I love the thought of interface -15. RFC4007 is looking
a bit sickly to me.

Regards
   Brian

On 02-Aug-21 10:21, Michael Richardson wrote:
> 
> Brian E Carpenter <brian.e.carpenter@gmail.com> wrote:
>     > On 01-Aug-21 23:30, Jürgen Schönwälder wrote:
>     >> The description statements in RFC 6991 talk about a zone index, i.e.,
>     >> they assume the zone index is numeric (which kind of follows from my
>     >> reading of RFC 4007).
>     >>
>     >> The pattern is flexible enough to accept a string as well (e.g., 
an
>     >> interface name). In other words, a server may accept 'fe80::1%lo0' as
>     >> valid input on an edit-config put it will return 'fe80::1%0' on a
>     >> get-config since the numeric zone index is the canonical format
>     >> (assuming the lo0 interface has the interface index 0).
> 
>     > This still makes me uncomfortable. The zone identifier syntax definition.
>     > in RFC4007 is pretty vague. If an implementer chooses to ignore the
>     > SHOULD on page 16, it seems that a valid name for interface index 
7
>     > could be "6". That's why "canonical" is a bit weak. (Neither Windows
>     > nor Linux allow anything that silly, of course.)
> 
> Is this what you mean... picking on an interface I'm not using today:
> 
> %ip link ls dev virbr0
> 15: virbr0: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
>     link/ether 52:54:00:14:c7:73 brd ff:ff:ff:ff:ff:ff
> %sudo ip link set name "15" dev virbr0
> %ip link ls dev virbr0
> Device "virbr0" does not exist.
> 
> %ip link ls dev 15
> 15: 15: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
>     link/ether 52:54:00:14:c7:73 brd ff:ff:ff:ff:ff:ff
> 
>     > An implementation SHOULD support at least numerical indices that are
>     > non-negative decimal integers as <zone_id>.
> 
> Oh.
> 
> %sudo ip link set name "-15" dev "15"
> %ip link ls dev -15
> 15: -15: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
>     link/ether 52:54:00:14:c7:73 brd ff:ff:ff:ff:ff:ff
> 
>     > An implementation MAY support other kinds of non-null strings as
>     > <zone_id>.
>     > ... the format MUST be used only within a
>     > node and MUST NOT be sent on the wire unless every node that
>     > interprets the format agrees on the semantics.
> 
> :-)
> 
>     > Remotely, there is no way to know that on my Linux machine,
>     > %wlp2s0 and %3 are the same thing.
> 
> Agreed.
> But, SNMP and YANG know.
> So if you are doing CORECONF, then you might want to encode stuff.
> 
> And if you want to set an IPv6-LL address for a daemon to listen on, then you
> need the scope.  That seems to be the place where we need this, and this
> would seem to be the use case.
> 
> (Looking back at my code involving IPsec configuration over LLv6, I see 
that
> actually, I am in trouble if v6LL addresses are ever duplicated, as I don't
> send the scope)
> 
> For the Interface form, adding a third (optional) field for scope is easy.
> I am open to suggestions for handling the Address format.
> 
> --
> Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
>            Sandelman Software Works Inc, Ottawa and Worldwide
> 
> 
> 
>