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

Ted Lemon <> Sun, 14 February 2021 15:43 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 55FDC3A0E1C for <>; Sun, 14 Feb 2021 07:43:08 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: 0.003
X-Spam-Status: No, score=0.003 tagged_above=-999 required=5 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=unavailable autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id pn39gVZ1QI_w for <>; Sun, 14 Feb 2021 07:43:06 -0800 (PST)
Received: from ( [IPv6:2607:f8b0:4864:20::82d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 99CA83A0E1D for <>; Sun, 14 Feb 2021 07:43:06 -0800 (PST)
Received: by with SMTP id e11so3260696qtg.6 for <>; Sun, 14 Feb 2021 07:43:06 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20150623; h=from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=atEpRfgUFHc9qSg6a7EYLvUv+SpHNSpjLTjPGpE1Agk=; b=yAN+M1/gttjnzsrN5iXY9LApJ/3lKnuKfSDoLiMDAGqgluifIlaTZWFAra9ndkTkbE kZ602NEogoqBP9BBG9LBPOJHeRoNCzuv4P4cRa6WbxLAlFYYiUKb2Z+STDUR9UYTA1fm 66AQ1AdeBk426PrcACs2IogbtCH8OluPNdZ0czuGXdtFPy/35NUVCBF9SWQ9oW/A8eId 0R1fMt18vRTCP+QdFZ6SGrqd19ErdrXEx4OpkZomscet3VX18oxObwRSl4TPq7exikj4 eMHjzpCnFZ2x874p+6BFLXTFAm/Pv/2d4PVqTS5JqwkQpUd2Gq9v4GtbkX1N49NK7F/W xNHw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:from:message-id:mime-version:subject:date :in-reply-to:cc:to:references; bh=atEpRfgUFHc9qSg6a7EYLvUv+SpHNSpjLTjPGpE1Agk=; b=fxUrfBTaNqt2CEAOY8ZO6ZByTZr9zyLGT6eYqBBTSHxzehJbbNAZZ+Q2b6l5L5E0Cs sAceZGhLjbnSaiP/eeSRtJ7uAxpN0RtSWwhJEaUrVHrtKP2y0HJ6nx+MVK8lNyMaHp+h 2jyhoQi4yXGCmp8ClJHc63KV6otwwEVewIx904owfeiheV2lYNIGa/TM9pczD+ZOU66T emFiWSQdLu+MjHFqPJdPXuI1XVosVUjkXr1r1d9Wl8jNQbW51hdjZ3FvzHqwCr8QVi+w rYCCOnnczLnME68ahJzuDfjDTWNCnf8qzokApv1fTEeav42fFCChhcSUKZinfi/Mqcap hx5w==
X-Gm-Message-State: AOAM5307Ah++UxJb1re9BXVCC0uzbucwrI2JhNAAK833FoEf3wSctABm /yGjMFjXD1TDNcXqVl75sCGVow==
X-Google-Smtp-Source: ABdhPJxfqZEV/4KGVoP/arZcltMhJp4XhljDHlZqViO55X1+HHyYg7UOXvI5FhYn7IY69IBB0PGvSg==
X-Received: by 2002:ac8:118c:: with SMTP id d12mr11001161qtj.262.1613317385476; Sun, 14 Feb 2021 07:43:05 -0800 (PST)
Received: from [] ( []) by with ESMTPSA id i5sm10573892qkg.32.2021. (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 14 Feb 2021 07:43:04 -0800 (PST)
From: Ted Lemon <>
Message-Id: <>
Content-Type: multipart/alternative; boundary="Apple-Mail=_ADE753A1-2E45-4A79-9957-075C5AF9DC12"
Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.\))
Subject: Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)
Date: Sun, 14 Feb 2021 10:43:03 -0500
In-Reply-To: <>
Cc: Brian E Carpenter <>, David Farmer <>, Fred Baker <>, IPv6 Operations <>, "" <>
To: Fernando Gont <>
References: <> <> <> <> <> <> <> <> <>
X-Mailer: Apple Mail (2.3654.
Archived-At: <>
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Sun, 14 Feb 2021 15:43:08 -0000

On Feb 14, 2021, at 1:00 AM, Fernando Gont <> wrote:
> IMO, if the areas overlap, the scope ofa ULA1 and ULA2 are still the same. One scope is Area(ULA1): all the area where ULA1 addresses are unique and can be actively employed. The other one is Area(ULA2).
> The intersection of the two areas is part of the scope of each of the two ULAs (because in that region both ULA1 and ULA2 are unambiguous)

Since you still haven’t clearly articulated what you mean by “scope” with respect to ULA, it doesn’t make sense to say that one ULA has the same or a different scope than another. In any case, what you are describing here is precisely what the “label” entry in an RFC 6724 policy table does. Which is to say, you are not talking about scopes.

> This is not that different from the overlap of e.g. link-locals and GUAs on a local link….

Since the different treatment of GUAs and LLAs on a link is something that can be known by definition, and thus be handled by if-then-else statements rather than by table lookups, I would say that they are quite different.