Re: Limited Domains:

Nick Hilliard <nick@foobar.org> Tue, 13 April 2021 09:57 UTC

Return-Path: <nick@foobar.org>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 75B293A107C; Tue, 13 Apr 2021 02:57:42 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, NICE_REPLY_A=-0.001, 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 HTB-HrwTjKHl; Tue, 13 Apr 2021 02:57:41 -0700 (PDT)
Received: from mail.netability.ie (mail.netability.ie [IPv6:2a03:8900:0:100::5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 8B93F3A0FCB; Tue, 13 Apr 2021 02:57:37 -0700 (PDT)
X-Envelope-To: draft-filsfils-6man-structured-flow-label@ietf.org
Received: from crumpet.local (admin.ibn.ie [46.182.8.8]) (authenticated bits=0) by mail.netability.ie (8.16.1/8.16.1) with ESMTPSA id 13D9vW60040225 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 13 Apr 2021 10:57:33 +0100 (IST) (envelope-from nick@foobar.org)
X-Authentication-Warning: cheesecake.ibn.ie: Host admin.ibn.ie [46.182.8.8] claimed to be crumpet.local
Subject: Re: Limited Domains:
To: "Ahmed Abdelsalam (ahabdels)" <ahabdels=40cisco.com@dmarc.ietf.org>
Cc: Tom Herbert <tom@herbertland.com>, Brian E Carpenter <brian.e.carpenter@gmail.com>, "draft-filsfils-6man-structured-flow-label@ietf.org" <draft-filsfils-6man-structured-flow-label@ietf.org>, "6man@ietf.org" <6man@ietf.org>
References: <BL0PR05MB5316991D4124AD85BC69392AAE709@BL0PR05MB5316.namprd05.prod.outlook.com> <1697a0f8-b3cd-9f7d-d610-305b5305c9a1@gmail.com> <4077E736-0092-44C6-80D1-E094F468C00C@gmail.com> <12878114-5c26-86f9-89c3-bcfa10141684@gmail.com> <CALx6S35NBfVJmjqVwhNV3nui2avUOXn6ySMG3cxx2AvGkwr_Ow@mail.gmail.com> <08A6C3D2-A81C-413A-81B3-EFAAA9DBCCE5@cisco.com>
From: Nick Hilliard <nick@foobar.org>
Message-ID: <5b68beb6-a6f9-828b-5cca-9c5ec2bfbea7@foobar.org>
Date: Tue, 13 Apr 2021 10:57:30 +0100
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:52.0) Gecko/20100101 PostboxApp/7.0.47
MIME-Version: 1.0
In-Reply-To: <08A6C3D2-A81C-413A-81B3-EFAAA9DBCCE5@cisco.com>
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/aRzjg6_-joZ97DIOpmOq1LLYvVw>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <ipv6.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipv6>, <mailto:ipv6-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ipv6/>
List-Post: <mailto:ipv6@ietf.org>
List-Help: <mailto:ipv6-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipv6>, <mailto:ipv6-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 13 Apr 2021 09:57:47 -0000

Ahmed Abdelsalam (ahabdels) wrote on 13/04/2021 09:59:
> [AA] I don't think we need a new codepoint.
> The operator explicitly configures the routers under his
> administrative domain to support Structured Flow Label.

a codepoint is a marker to cause something to be interpreted in a 
specific and different way.  Moving this flag to the configuration 
domain is essentially admitting that the semantics of a codepoint are 
necessary, except that it removes the possibility of having these 
semantics interpreted automatically on a per-packet basis, and turns it 
into a per-router or possibly per-interface flag.  This is an unusual 
type of regression in terms of a protocol where so much work has been 
put into auto-configuration, and where the syntactic mechanism has been 
created for protocol extensions.

As a separate issue, if a regular ip packet from the outside 
accidentally enters into this administrative domain, how does a router 
on the inside of the domain know not to attempt to interpret the flow 
label as a SFL, as it could end up effectively parsing random junk?

Nick