Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)

Brian E Carpenter <brian.e.carpenter@gmail.com> Sun, 14 February 2021 22:41 UTC

Return-Path: <brian.e.carpenter@gmail.com>
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 6029F3A0CBB; Sun, 14 Feb 2021 14:41:36 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.199
X-Spam-Level:
X-Spam-Status: No, score=-0.199 tagged_above=-999 required=5 tests=[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, 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=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 xOs9wK1yRXiq; Sun, 14 Feb 2021 14:41:35 -0800 (PST)
Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) (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 007723A0CC4; Sun, 14 Feb 2021 14:41:03 -0800 (PST)
Received: by mail-pl1-x635.google.com with SMTP id k22so2689507pll.6; Sun, 14 Feb 2021 14:41:03 -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=db152U84fMqnnkV2RRnUSNmSSLa0lt5Bh9ZFOFgYhd0=; b=Ks0ZEp8kx9cUC9HwrNveUh3nEyQgtFWfhL8G3syuhKz/pae6gVneHHpLUor9FqJRR8 QbnKFg6RhFdTx/j+/tIoPKIfwMliYXKN/bjY5lct3Z4jMZjs9Q0O7wmUey+/yiJjx8u/ QislFjQD+QoHeTGC3fhgfhJZLnrb14GU4PQTaARu2V6PSc2JKG1Y10dgNfM9r5HBOGOP tnUEwK1oqfRFK2y0n17y868Akma1NB72b0G+d4a4A0FNDLGf6r7OphyZDZcyhgUiPqJi G4xGMFYVTZO+yOnA0n5eo8eEUJr+TWGyZ9koklxQryxgQpwyewf02j1mwXm4jBN5jeKN A/9Q==
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=db152U84fMqnnkV2RRnUSNmSSLa0lt5Bh9ZFOFgYhd0=; b=ocPJuSw1UA0G8WYybNUVtFEQ9+j+gtEb6iY7EWRzSAIkh2IOC57r/We7o8HlJ1K3Ew 1ncg/WTS0/B0snRXqVu7LBshW0ILXPLj0LNilOwI2ffDdhKcIzub3G1VkGax8pj/3lko es2odtAHUzvFd0x5yQtSVCpbbPPjJF+bYG35XNwieWjezU4MTSU0LvELuybddrBtnIt8 o6hIK0VfeOmFLKRLTmeJ7A4JUI5BcuIAaDRf55uAkq9fyIstZNENZ9duXbpBkcUmZtH+ dumeYgx4wAZE78k9dHEcssOFq/Gb3DzJvPJv1S2y4clo7sD5+w7Fu8Jua7dB9S7ahNQx yfXA==
X-Gm-Message-State: AOAM530LlzpDfoHfsA8npllbsCUHG2PxKHTgfRiYCRbqGFCPG6rbZZoa zCGnKJvyFIsaddvQtO468l38NoRCuAJeIA==
X-Google-Smtp-Source: ABdhPJw+aOEsa4xBON8cNAPlXVHGGW8ZBSy5icMbqTvpTcrkoNcLdVX2jDzlF4YdimCHUUV70Ra1dA==
X-Received: by 2002:a17:90b:4b02:: with SMTP id lx2mr13434899pjb.178.1613342463085; Sun, 14 Feb 2021 14:41:03 -0800 (PST)
Received: from [192.168.178.20] ([151.210.131.28]) by smtp.gmail.com with ESMTPSA id o185sm15027346pfb.196.2021.02.14.14.41.00 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 14 Feb 2021 14:41:02 -0800 (PST)
Subject: Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)
To: Fernando Gont <fgont@si6networks.com>, Ted Lemon <mellon@fugue.com>
Cc: David Farmer <farmer@umn.edu>, Fred Baker <fredbaker.ietf@gmail.com>, IPv6 Operations <v6ops@ietf.org>, "6man@ietf.org" <6man@ietf.org>
References: <160989494094.6024.7402128068704112703@ietfa.amsl.com> <6fe3a45e-de65-9f88-808d-ea7e2abdcd16@si6networks.com> <F4E00812-E366-4520-AE17-7BB46E28D575@gmail.com> <CAN-Dau3iOjjU+FLpdtA7nqfKRX+sjjSanAU8U-O3pH-k5nSoig@mail.gmail.com> <a3fbfb94-90ae-961c-a2ab-33ade27e074e@si6networks.com> <672bd5e6-bdce-5915-1082-1ed30d3c5980@gmail.com> <f65952f1-fcd1-0918-4dd8-256f822524ee@si6networks.com> <886ad526-b62c-aef2-96ca-62e7829692b5@gmail.com> <8ed7f569-9ee8-08d6-cf17-a72bc2c7b854@si6networks.com> <B364BF30-23F1-497A-8928-5AB0D718204B@fugue.com> <30730d0f-5a90-f7ce-d9ce-6f4aef75bde2@si6networks.com> <9DD46169-462F-454B-A5B2-26FCB1B0C6EF@fugue.com> <ab86907f-0efc-8b7d-e4b6-1482418b4ef8@si6networks.com> <A68D439D-A493-40F0-ACE3-0C52ACD8F92D@fugue.com> <ccd6e531-9bbd-25cd-4763-26646146d293@si6networks.com>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Message-ID: <5f75cf75-76c1-5c3c-bd1e-2797592cd927@gmail.com>
Date: Mon, 15 Feb 2021 11:40:57 +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: <ccd6e531-9bbd-25cd-4763-26646146d293@si6networks.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/3RZoIJCFE6TCeqa0oCKKx829hC0>
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: Sun, 14 Feb 2021 22:41:36 -0000

On 15-Feb-21 10:54, Fernando Gont wrote:
> On 14/2/21 18:34, Ted Lemon wrote:
>> On Feb 14, 2021, at 4:14 PM, Fernando Gont <fgont@si6networks.com 
>> <mailto:fgont@si6networks.com>> wrote:
>>> That's not a legitimate use for GUAs.  Whereas in the case of ULAs, 
>>> that the *intended* usage.
>>
>> Untrue. ULAs are intended to be globally unique. 
> 
> Could you compute the birthday paradox for *all ULAs* on the internet, 
> and share the math/results?

I'm not Ted, and my preferred formulation is:

   ULAs are intended to be globally unique for all practical purposes.

Although there is a high probability of some ULA prefixes somewhere
being equal, the probability of your ULA prefix being equal to your
next-door neighbour's is extremely small.

There's no equivalent statement that can be made for RFC 1918 addresses,
nor for the deprecated IPv6 Site Local addresses.

BTW, RFC 4193 seems very clear on this to me:

>>       - Globally unique prefix (with high probability of uniqueness).
...
>>       - In practice, applications may treat these addresses like global
>>         scoped addresses.

    Brian