IETF Logo Mail Archive

Re: [babel] About ICMP and unnumbered routers

Juliusz Chroboczek <jch@irif.fr> Mon, 03 August 2020 16:26 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 7CF1D3A0F33 for <babel@ietfa.amsl.com>; Mon, 3 Aug 2020 09:26:26 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 0
X-Spam-Level:
X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham 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 wSCu7GBcI1xg for <babel@ietfa.amsl.com>; Mon, 3 Aug 2020 09:26:24 -0700 (PDT)
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 9C6643A0C99 for <babel@ietf.org>; Mon, 3 Aug 2020 09:26:24 -0700 (PDT)
Received: from potemkin.univ-paris7.fr (potemkin.univ-paris7.fr [IPv6:2001:660:3301:8000::1:1]) by korolev.univ-paris7.fr (8.14.4/8.14.4/relay1/82085) with ESMTP id 073GQIfg017406 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 3 Aug 2020 18:26:18 +0200
Received: from mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [81.194.30.253]) by potemkin.univ-paris7.fr (8.14.4/8.14.4/relay2/82085) with ESMTP id 073GQITX026783; Mon, 3 Aug 2020 18:26:18 +0200
Received: from mailhub.math.univ-paris-diderot.fr (localhost [127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTP id 9838DBF706; Mon, 3 Aug 2020 18:26:18 +0200 (CEST)
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 9piCXsBB3Lqi; Mon, 3 Aug 2020 18:26:17 +0200 (CEST)
Received: from pirx.irif.fr (unknown [78.194.40.74]) (Authenticated sender: jch) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTPSA id D49B5BF6F7; Mon, 3 Aug 2020 18:26:14 +0200 (CEST)
Date: Mon, 03 Aug 2020 18:26:14 +0200
Message-ID: <87h7tjk861.wl-jch@irif.fr>
From: Juliusz Chroboczek <jch@irif.fr>
To: "STARK, BARBARA H" <bs7652@att.com>
Cc: 'Babel at IETF' <babel@ietf.org>
In-Reply-To: <53db6ea1f66a40f5936106357157e25d@att.com>
References: <87pn88kgs0.wl-jch@irif.fr> <CAF4+nEGKM3_U49-79bD3eQs+SK8G4Q5oCr_WEYF8iP5+mdTDLQ@mail.gmail.com> <53db6ea1f66a40f5936106357157e25d@att.com>
User-Agent: Wanderlust/2.15.9
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset="US-ASCII"
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (korolev.univ-paris7.fr [IPv6:2001:660:3301:8000::1:2]); Mon, 03 Aug 2020 18:26:19 +0200 (CEST)
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (potemkin.univ-paris7.fr [194.254.61.141]); Mon, 03 Aug 2020 18:26:18 +0200 (CEST)
X-Miltered: at korolev with ID 5F283AAA.001 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)!
X-Miltered: at potemkin with ID 5F283AAA.000 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)!
X-j-chkmail-Enveloppe: 5F283AAA.001 from potemkin.univ-paris7.fr/potemkin.univ-paris7.fr/null/potemkin.univ-paris7.fr/<jch@irif.fr>
X-j-chkmail-Enveloppe: 5F283AAA.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 : 5F283AAA.001 on korolev.univ-paris7.fr : j-chkmail score : . : R=. U=. O=. B=0.000 -> S=0.000
X-j-chkmail-Score: MSGID : 5F283AAA.000 on potemkin.univ-paris7.fr : j-chkmail score : . : R=. U=. O=. B=0.000 -> S=0.000
X-j-chkmail-Status: Ham
X-j-chkmail-Status: Ham
Archived-At: <https://mailarchive.ietf.org/arch/msg/babel/Jl5HORealDkbUAxpmQTOnQzzlOY>
Subject: Re: [babel] About ICMP and unnumbered routers
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: Mon, 03 Aug 2020 16:26:27 -0000

> Has an RFC 5735 169.254.0.0/16 IPv4 link local address been considered?
> Do the ICMP packets need to cross routed boundaries?

Yes.  If there's an MTU mismatch and a packet has the DF bit set, then the
router needs to send back a Packet Too Big message to the originator, else
a blackhole will occur (except if RFC 4821 is implemented, but even if it
is, PTB packets make convergence faster).

Note howver, that I'm not sure whether routers block packets with
169.254/16 in the *source* address (as opposed to the destination).

-- Juliusz

v2.46.0 | Report a Bug | By Email | System Status