Re: [v6ops] I-D Action: draft-gont-v6ops-ipv6-addressing-considerations-00.txt

Brian E Carpenter <brian.e.carpenter@gmail.com> Thu, 31 December 2020 19:47 UTC

Return-Path: <brian.e.carpenter@gmail.com>
X-Original-To: v6ops@ietfa.amsl.com
Delivered-To: v6ops@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 22A6E3A08C5; Thu, 31 Dec 2020 11:47:37 -0800 (PST)
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, FREEMAIL_FROM=0.001, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.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 XAmqHggQVNlg; Thu, 31 Dec 2020 11:47:35 -0800 (PST)
Received: from mail-pg1-x535.google.com (mail-pg1-x535.google.com [IPv6:2607:f8b0:4864:20::535]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id E15223A08BD; Thu, 31 Dec 2020 11:47:35 -0800 (PST)
Received: by mail-pg1-x535.google.com with SMTP id g15so13523679pgu.9; Thu, 31 Dec 2020 11:47:35 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=SsqagLPtKzm1ijS0nbH9eTvO6wn4Oes5xwT875AUme0=; b=mdUjE6N6zOQ1HU4cx9TSzXYd5GH8porTrxm3VEDnByCUcrIT3sacXnQVqkFDCJVmct kZY/v3T3RM7FIV/6ZXOwsIHugTM3eMa+b1srzcLup4LcO6ctPghoHlLO241Lo28ErSUc pc8FMEUDq1YcngXDao+2naqOl5tyB4vqqNnZ7j37mN/KkOeb8h/zvOLvfrrDCYvn4ZU6 s54qoGjsTCCj2FKEHlGc5XPVQlLHaMzutBqPA+ETSO2BIQqx8/2TMLWm21oIRKU8ZuKK nQEly1sSKY4/BCT959Stv7jvxNc9AS+bu0kZCtR3f+iho4HxpN7LdhU0l/6pKNq77vo6 XzKw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=SsqagLPtKzm1ijS0nbH9eTvO6wn4Oes5xwT875AUme0=; b=XKJOMalh7ZESO3WtuRn6Q1T3bNdN1g0zXKe15ns2V45cyJzkddNZLjLZsjHQnvkWNJ vXcSK3ps8kb8D/A5w9yuBBai7vRlHmmc+t+1bW8PsZaiKbZIP8jwGZqkXQxXV+2TiV+k xyOt/sTUxEiecs+ZEZMs07FapjblNnZxiw947+rPqR3ts7qBllaiONAhNVolLBIs1N2v Gl/gtmsaULY68waJYC4alouC6WpNYeY+AUi/N2XMVw2ASqSlUCKmwl78yj7VxizXB8IB WyC5oRNf805Ax0R6VnaKIPQLxAhQktnEnq9PEuzDHQCvI2PwfnKCOwdJIFVZ07W++CN5 Fjow==
X-Gm-Message-State: AOAM532e53Crp8w1u7d0BWYEYyC/KQb1otoCpRGQgJcx+Xmm/D87lrrK OwOw9jWoE/MPQwxPKGHNP3oWNZ0ukPaceQ==
X-Google-Smtp-Source: ABdhPJyVPAZm7lcGnmZAssqxYVo3JXVKaM1FTXiiVQK7YeesdN5M33aIUtapXrT7R1C5+Aia6t9Dvw==
X-Received: by 2002:a65:4983:: with SMTP id r3mr58873733pgs.288.1609444054969; Thu, 31 Dec 2020 11:47:34 -0800 (PST)
Received: from [192.168.178.20] ([151.210.131.28]) by smtp.gmail.com with ESMTPSA id e6sm11211811pjr.34.2020.12.31.11.47.32 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 31 Dec 2020 11:47:34 -0800 (PST)
To: Gert Doering <gert@space.net>
Cc: Fernando Gont <fgont@si6networks.com>, IPv6 Operations <v6ops@ietf.org>, draft-gont-v6ops-ipv6-addressing-considerations@ietf.org
References: <160770241261.18071.12524922630334294118@ietfa.amsl.com> <fb832698-039e-baa5-ed6f-4d5a97e7b354@gmail.com> <299f492f-4cb7-fa9d-967f-b2a5df49034e@si6networks.com> <759efdb1-a59c-788c-0c7a-5a8ca2ced904@gmail.com> <b20425a3-8069-3823-4610-79c93714ad2f@si6networks.com> <fa8c56d3-5d64-ae55-5be1-a3ec7d8f130d@gmail.com> <20201231103010.GL13005@Space.Net>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Message-ID: <47fb8588-98ee-bf50-b377-921f75dc72e0@gmail.com>
Date: Fri, 1 Jan 2021 08:47:31 +1300
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1
MIME-Version: 1.0
In-Reply-To: <20201231103010.GL13005@Space.Net>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/v6ops/bFh701KrAtuN7oT-KJXb1xKTXSw>
Subject: Re: [v6ops] I-D Action: draft-gont-v6ops-ipv6-addressing-considerations-00.txt
X-BeenThere: v6ops@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: v6ops discussion list <v6ops.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/v6ops>, <mailto:v6ops-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/v6ops/>
List-Post: <mailto:v6ops@ietf.org>
List-Help: <mailto:v6ops-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v6ops>, <mailto:v6ops-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 31 Dec 2020 19:47:37 -0000

Gert,

On 31-Dec-20 23:30, Gert Doering wrote:
> Hi,
> 
> On Thu, Dec 31, 2020 at 02:00:33PM +1300, Brian E Carpenter wrote:
>> 4. The following table attempts to show some of the distinctions
>> involved (simplified). View in a fixed-width font. You may not
>> agree with it...
>>
>> Unicast       Prefix      IID        Routeable   Announced
>> address       assigned    assigned
>> types         by          by
>> -----------------------------------------------------------
>> Link-local    fixed       host       no          no
>>               by RFC
>>   
>> ULA           user/RA     host or    yes         IGP only
>>               (random)    DHCPv6
>>
>> GUA           IANA/RIR/   host or    yes         IGP,
>>               ISP/user/RA DHCPv6                 BGP4 by policy
> 
> Indeed, I am not agreeing - as there is nothing that prevents ULAs from 
> being transported by BGP.

Indeed, nothing in the laws of physics, but it's default-forbidden by
an RFC ;-). Exactly how to express that in a short table is tricky.

I think we all agree about this; what Fernando's draft shows is that it
is quite hard to describe, and the word "global" is confusing.
(Really for the same reason that URLs were renamed from "universal"
to "uniform" in 1994. But renaming "global" at this stage seems almost
impossible.)

   Brian

> 
> We use ULAs for "services that must never reachable from the Internet",
> and our routing being what it is, everything is transported by BGP - only
> loopbacks in OSPF.  The difference is "do we announce it to other ASes?"
> 
> So maybe this should be "generally expected to be visible by other
> networks on the Internet" (ULA: no, GUA: yes).
> 
> But that's neither precise nor does "expected" mandate anything - I might
> want to announce our ULA prefix to our sister company, using eBGP, and
> I might decide to not announce our GUA IPv6 PI /48 that we use for our
> backbone infra "because people are not supposed to send packets there"...
> 
> Gert Doering
>         -- NetMaster
>