Re: [babel] proposed info model change

Juliusz Chroboczek <jch@irif.fr> Fri, 26 February 2021 19:27 UTC

Return-Path: <jch@irif.fr>
X-Original-To: babel@ietfa.amsl.com
Delivered-To: babel@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id CC1503A159A for <babel@ietfa.amsl.com>; Fri, 26 Feb 2021 11:27:03 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=unavailable autolearn_force=no
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 gnfiLn2PZISn for <babel@ietfa.amsl.com>; Fri, 26 Feb 2021 11:27:02 -0800 (PST)
Received: from korolev.univ-paris7.fr (korolev.univ-paris7.fr [IPv6:2001:660:3301:8000::1:2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 057363A1596 for <babel@ietf.org>; Fri, 26 Feb 2021 11:27:01 -0800 (PST)
Received: from mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [81.194.30.253]) by korolev.univ-paris7.fr (8.14.4/8.14.4/relay1/82085) with ESMTP id 11QJQuF3023781; Fri, 26 Feb 2021 20:26:56 +0100
Received: from mailhub.math.univ-paris-diderot.fr (localhost [127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTP id 19001108410; Fri, 26 Feb 2021 20:26:56 +0100 (CET)
X-Virus-Scanned: amavisd-new at math.univ-paris-diderot.fr
Received: from mailhub.math.univ-paris-diderot.fr ([127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id BG58ZRBZ38G8; Fri, 26 Feb 2021 20:26:54 +0100 (CET)
Received: from pirx.irif.fr (unknown [78.194.40.74]) (Authenticated sender: jch) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTPSA id 1AB1710840E; Fri, 26 Feb 2021 20:26:54 +0100 (CET)
Date: Fri, 26 Feb 2021 20:26:54 +0100
Message-ID: <87eeh2iq9t.wl-jch@irif.fr>
From: Juliusz Chroboczek <jch@irif.fr>
To: "STARK, BARBARA H" <bs7652@att.com>
Cc: "'Mahesh Jethanandani'" <mjethanandani@gmail.com>, "'David Schinazi'" <dschinazi.ietf@gmail.com>, "'Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen=27?=" <toke=40toke.dk@dmarc.ietf.org>, "'babel@ietf.org'" <babel@ietf.org>
In-Reply-To: <DM6PR02MB69249CEAAB32A391274A8ED3C38B9@DM6PR02MB6924.namprd02.prod.outlook.com>
References: <DM6PR02MB6924E3E2DD5568E247859E18C38C9@DM6PR02MB6924.namprd02.prod.outlook.com> <87blcqpau7.fsf@toke.dk> <E5F69D0C-7130-42D3-9080-C2EE5786D917@gmail.com> <878s7up8n0.fsf@toke.dk> <CAPDSy+6YWPr81uKHrWYoY=TZ0A18A_Ui3=CyLP=1K-ezwmgF-g@mail.gmail.com> <DBBE09E1-F407-4B5A-A096-669E74F25FB4@gmail.com> <DM6PR02MB69249CEAAB32A391274A8ED3C38B9@DM6PR02MB6924.namprd02.prod.outlook.com>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/27.1 Mule/6.0
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (korolev.univ-paris7.fr [194.254.61.138]); Fri, 26 Feb 2021 20:26:56 +0100 (CET)
X-Miltered: at korolev with ID 60394B80.000 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)!
X-j-chkmail-Enveloppe: 60394B80.000 from mailhub.math.univ-paris-diderot.fr/mailhub.math.univ-paris-diderot.fr/null/mailhub.math.univ-paris-diderot.fr/<jch@irif.fr>
X-j-chkmail-Score: MSGID : 60394B80.000 on korolev.univ-paris7.fr : j-chkmail score : . : R=. U=. O=. B=0.000 -> S=0.000
X-j-chkmail-Status: Ham
Archived-At: <https://mailarchive.ietf.org/arch/msg/babel/HCWD3qE2T7D6_7nMiV7A3ZsBaCk>
Subject: Re: [babel] proposed info model change
X-BeenThere: babel@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "A list for discussion of the Babel Routing Protocol." <babel.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/babel>, <mailto:babel-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/babel/>
List-Post: <mailto:babel@ietf.org>
List-Help: <mailto:babel-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/babel>, <mailto:babel-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 26 Feb 2021 19:27:04 -0000

> An enabled Babel instance (that is sending and receiving Babel packets) already
> has a requirement for unique non-zero router-id. Where we were having a problem
> was with not-enabled Babel instances that weren’t actively running the protocol
> (had maybe just been installed). I think it was babeld that was just using a
> default of all zeroes until it was enabled; at which time it generated its
> unique router-id. With this not-enabled “zero” default, the possibility exists
> for multiple not-enabled Babel instances to be defaulted to zero, which would
> lead to YANG having a problem with having a unique router-id to identify them
> by.

It's not an implementation problem, it's a protocol issue.

In the protocol, the router-id only appears on the wire when a router
redistributes (originates) a route.  If a router is not originating
routes, because it is only connected to transit networks, it does not need
a router-id.

So in this case, the information model would be imposing a slightly
stronger requirement on implementations than the core protocol: in order
to implement the information model, a router would need to draw a router-id
for itself even if it is only connected to transit networks.

I don't find this requirement too onerous, and I don't mind the
information model making it.

-- Juliusz