IETF Logo Mail Archive

Re: [netmod] 6021 ipv4-prefix

"Rob Wilton (rwilton)" <rwilton@cisco.com> Wed, 01 May 2019 16:21 UTC

Return-Path: <rwilton@cisco.com>
X-Original-To: netmod@ietfa.amsl.com
Delivered-To: netmod@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8EC881200D5 for <netmod@ietfa.amsl.com>; Wed, 1 May 2019 09:21:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.502
X-Spam-Level:
X-Spam-Status: No, score=-14.502 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cisco.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 0v_oLPhGbO7j for <netmod@ietfa.amsl.com>; Wed, 1 May 2019 09:21:39 -0700 (PDT)
Received: from alln-iport-7.cisco.com (alln-iport-7.cisco.com [173.37.142.94]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id D0CE612011A for <netmod@ietf.org>; Wed, 1 May 2019 09:21:38 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=2217; q=dns/txt; s=iport; t=1556727698; x=1557937298; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=6ojzKe04Wmm6wlOiOcFcCMMzMXz28DBUo/sgKR4m6i0=; b=aFsGw+iH7/JpiepVUrIhYrwlVCypbJaUanj5GyzXTUI8YhdoLCzrOl+Y 2wmNs09DiYznEe6aeC9NVYK0fJ56XkFtSGiVsj7IvK+QcCVbQwSXYVg8h KylcsumQN1zz/N0XCccY0mn00d5CJWabQPvPciipohewvRRzXQVc9Ziwg A=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: A0AHAADExslc/5BdJa1mGQEBAQEBAQEBAQEBAQcBAQEBAQGBUwIBAQEBAQsBghCBbSgKmTWYUIF7DgEBhG0ChjIjNgcOAQMBAQQBAQIBAm0ohUoBAQEBAzo/DAQCAQgOAgEEAQEBHhAyHQgCBAENBQgThRKvOYo1gTIBi0sXgUA/hCM+hC6FeASnEwkCggmSNyOVNYwRlFwCERWBMCUBMYFWcBWDJ5BRQTGSU4EhAQE
X-IronPort-AV: E=Sophos;i="5.60,418,1549929600"; d="scan'208";a="265386165"
Received: from rcdn-core-8.cisco.com ([173.37.93.144]) by alln-iport-7.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 01 May 2019 16:21:38 +0000
Received: from XCH-ALN-006.cisco.com (xch-aln-006.cisco.com [173.36.7.16]) by rcdn-core-8.cisco.com (8.15.2/8.15.2) with ESMTPS id x41GLcei029233 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=FAIL); Wed, 1 May 2019 16:21:38 GMT
Received: from xch-rcd-007.cisco.com (173.37.102.17) by XCH-ALN-006.cisco.com (173.36.7.16) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 1 May 2019 11:21:37 -0500
Received: from xch-rcd-007.cisco.com ([173.37.102.17]) by XCH-RCD-007.cisco.com ([173.37.102.17]) with mapi id 15.00.1473.003; Wed, 1 May 2019 11:21:37 -0500
From: "Rob Wilton (rwilton)" <rwilton@cisco.com>
To: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>, Mikael Abrahamsson <swmike@swm.pp.se>
CC: "netmod@ietf.org" <netmod@ietf.org>
Thread-Topic: [netmod] 6021 ipv4-prefix
Thread-Index: AdT0l4zGpLjvUofYRmmSWqlDWwoAHABSPgGAAAHDNYAAA12WgAABgE0AAAD0FQAAAKy0gAF1SI2AAAERvAAAFIrFgAAG4xuAAADAhYAACALZAAAA/vaAAAK/LwAAATq3AAB768IgAAtOeIAACmVD4P//tfSAgABTU/D//+IngIAAUdRQ//+41wCAAFEEMP//wy6AABznDYAAAdzWgAAFM7gAAADJUIAAMdJaAAAE8bQAAAQJZoAABZuUgAAKXFbA
Date: Wed, 01 May 2019 16:21:37 +0000
Message-ID: <c57787c046cd4e94a8d27413dbe79a12@XCH-RCD-007.cisco.com>
References: <0c4265d31adbf208a680f76216cc4bc42c766eae.camel@nic.cz> <959ed1a8092f4798ac0b923384962049@XCH-RCD-007.cisco.com> <20190429153643.oxfcq7ze6ttdihb4@anna.jacobs.jacobs-university.de> <alpine.DEB.2.20.1904300713100.3490@uplift.swm.pp.se> <20190430061737.vvxghxyacd57k73i@anna.jacobs.jacobs-university.de> <alpine.DEB.2.20.1904301038570.3490@uplift.swm.pp.se> <20190430090905.qsa3r4dwauilsxur@anna.jacobs.jacobs-university.de> <alpine.DEB.2.20.1905011051160.1824@uplift.swm.pp.se> <20190501111712.347bpz26br6ox3jp@anna.jacobs.jacobs-university.de> <alpine.DEB.2.20.1905011456580.1824@uplift.swm.pp.se> <20190501155321.v4qz6twsom45y62f@anna.jacobs.jacobs-university.de>
In-Reply-To: <20190501155321.v4qz6twsom45y62f@anna.jacobs.jacobs-university.de>
Accept-Language: en-GB, en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [10.63.23.60]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-Outbound-SMTP-Client: 173.36.7.16, xch-aln-006.cisco.com
X-Outbound-Node: rcdn-core-8.cisco.com
Archived-At: <https://mailarchive.ietf.org/arch/msg/netmod/OeXqzmjkGDdi4igaell2qMtWzeo>
Subject: Re: [netmod] 6021 ipv4-prefix
X-BeenThere: netmod@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: NETMOD WG list <netmod.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/netmod>, <mailto:netmod-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/netmod/>
List-Post: <mailto:netmod@ietf.org>
List-Help: <mailto:netmod-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/netmod>, <mailto:netmod-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 01 May 2019 16:21:41 -0000


> -----Original Message-----
> From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
> Sent: 01 May 2019 16:53
> To: Mikael Abrahamsson <swmike@swm.pp.se>
> Cc: Rob Wilton (rwilton) <rwilton@cisco.com>; netmod@ietf.org
> Subject: Re: [netmod] 6021 ipv4-prefix
> 
> On Wed, May 01, 2019 at 03:12:47PM +0200, Mikael Abrahamsson wrote:
> >
> > I am fine with c), but I am also saying I disagree with your view that
> > this this behaviour has been specified "since the beginning". This
> > might have been obvious to you from the beginning, but it's not
> > wrotten down properly (at least I haven't seen text that makes me
> > clearly understand the expected behaviour). I think the text
> > specifying what "canonical format is" referring to "same *value*" is
> > wrong. +17 and 17 is the same integer, 192.168.0.1/24 and
> > 192.168.0.0/24 are not the same *value*. It's misleading to refer to
> > the canonical form having the *same* *value* when we're throwing away
> information.
> >
> 
> The basic disconnect here may be that for me the prefix is the value while for
> you the value is the prefix plus the unused bits.

[To frame this comment, I don't object to your currently proposed solution]

I consider the extra bits after the valid part of the prefix to be unwanted noise.

For me, one hypothetical question I have is whether the potential convenience of allowing 192.168.0.1/24 (for some use cases) outweighs the risk that the wrong value has been provided but cannot be checked (e.g. 192.168.0.1/2).

Similarly, if you consider strings with a max length, I would expect a server to reject a configured string that was too long rather that treat the excessive characters as noise and silently truncate the input.

If it was down to me, and I was defining this now, then I would choose the stricter input (as per the should currently in the ipv6-prefix definition).  But no longer care if the consensus is in the other direction.

Whichever way we change the definitions, I believe that they are being changed in a non-backwards-compatible way that will impact some clients or server implementations.

Thanks,
Rob

v2.23.0 | Report a Bug | By Email