Re: [dhcwg] [v6ops] [EXTERNAL] Re: Question to DHCPv6 Relay Implementors regarding draft-ietf-dhc-dhcpv6-pd-relay-requirements

"Templin (US), Fred L" <Fred.L.Templin@boeing.com> Fri, 09 October 2020 14:02 UTC

Return-Path: <Fred.L.Templin@boeing.com>
X-Original-To: dhcwg@ietfa.amsl.com
Delivered-To: dhcwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 6E8D33A047D; Fri, 9 Oct 2020 07:02:10 -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, 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=boeing.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 Z3eixSU9PYV6; Fri, 9 Oct 2020 07:02:08 -0700 (PDT)
Received: from clt-mbsout-02.mbs.boeing.net (clt-mbsout-02.mbs.boeing.net [130.76.144.163]) (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 D32A33A0407; Fri, 9 Oct 2020 07:02:07 -0700 (PDT)
Received: from localhost (localhost [127.0.0.1]) by clt-mbsout-02.mbs.boeing.net (8.15.2/8.15.2/DOWNSTREAM_MBSOUT) with SMTP id 099E20NZ025121; Fri, 9 Oct 2020 10:02:04 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=boeing.com; s=boeing-s1912; t=1602252124; bh=ABepccQDrq2BhE+kMPtBhaefuCFRL0hPmYLFSle8gC4=; h=From:To:CC:Subject:Date:References:In-Reply-To:From; b=a3q2ujM1wxbFj+lcrV+osmVD+fuaFzihfdUzbyiU3dGrG23oIZtZkubonyXwDSLwj ZhamdMyBZhvVLAxir62oBPIgHabZoAniem92Ail8iM1t8ZyEt8zWSguTR/Skey9LRS 7COB1i41ymJv1j6cQIqgR9beWE/bWgU17RtJQR7l65ACpTtUdzpEzI9G6YVHYmzd4l 8FoxYOYlLGF1OlRgCrhqEaCqOk6N9jRmGVRM7V0uHixm4iqb/7TY6B+AvtAC7UBM1G V4dQynpJwJthRT73aRW5RIhUmJhXB65iXb5t6QrSNXWhikNRXC2Nh3sIWRgjzETDhH 06fTM3MIMhI2Q==
Received: from XCH16-07-10.nos.boeing.com (xch16-07-10.nos.boeing.com [144.115.66.112]) by clt-mbsout-02.mbs.boeing.net (8.15.2/8.15.2/8.15.2/UPSTREAM_MBSOUT) with ESMTPS id 099E1t9r024778 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=OK); Fri, 9 Oct 2020 10:01:55 -0400
Received: from XCH16-07-10.nos.boeing.com (144.115.66.112) by XCH16-07-10.nos.boeing.com (144.115.66.112) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.2044.4; Fri, 9 Oct 2020 07:01:54 -0700
Received: from XCH16-07-10.nos.boeing.com ([fe80::e065:4e77:ac47:d9a8]) by XCH16-07-10.nos.boeing.com ([fe80::e065:4e77:ac47:d9a8%2]) with mapi id 15.01.2044.004; Fri, 9 Oct 2020 07:01:54 -0700
From: "Templin (US), Fred L" <Fred.L.Templin@boeing.com>
To: Ole Troan <otroan@employees.org>
CC: dhcwg <dhcwg@ietf.org>, v6ops list <v6ops@ietf.org>, 6man <ipv6@ietf.org>
Thread-Topic: [dhcwg] [v6ops] [EXTERNAL] Re: Question to DHCPv6 Relay Implementors regarding draft-ietf-dhc-dhcpv6-pd-relay-requirements
Thread-Index: AQHWnkS+UHZEXbeyVUaRnVx7EHKeyA==
Date: Fri, 09 Oct 2020 14:01:54 +0000
Message-ID: <5fd7f95f054e4c6fb91d245e4a9a016a@boeing.com>
References: <ff36a6d9f0834b5bbf331c6c40df16b8@boeing.com> <6373DDB1-753B-4E15-8097-9ED03F1BFC19@employees.org> <5b45336f7d9d489bb13a3559fd0a6b10@boeing.com> <66fcc6c4c1d243108b6b2eb19719324c@boeing.com>
In-Reply-To: <66fcc6c4c1d243108b6b2eb19719324c@boeing.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [137.137.12.6]
x-tm-snts-smtp: 309C4EDF93173310AE3BADB98E696B96979A1481187BA1BD119A7121870EDCFF2000:8
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-TM-AS-GCONF: 00
Archived-At: <https://mailarchive.ietf.org/arch/msg/dhcwg/9YER3yuaMzg-zJxE3IQnThWyWGg>
Subject: Re: [dhcwg] [v6ops] [EXTERNAL] Re: Question to DHCPv6 Relay Implementors regarding draft-ietf-dhc-dhcpv6-pd-relay-requirements
X-BeenThere: dhcwg@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <dhcwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dhcwg/>
List-Post: <mailto:dhcwg@ietf.org>
List-Help: <mailto:dhcwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 09 Oct 2020 14:02:11 -0000

Responding to myself since folks seem to have blasted past this proposal:

> So, why not fix the problem at the client instead of at the relay? The client could
> have a simple check to make sure it does not forward a packet out the same
> interface that it arrived on due to a default route. That way, the relay would
> never see a packet originating from node A with a destination address A.
> (BTW, it should be OK for the client to forward a packet out the same interface
> it arrived on due to  a more-specific route - but not due to a default route.)

The problem that is being described is a client problem; not a relay problem.
So, why not fix it in the client? Fixing it in the client also avoids wasted message
transmissions on the link from the client to the relay since packets that would
cause a loop would never be transmitted by the client at all. This is very important
for some link types such as aviation data links where the data rates are low to
begin with.

Fred