Re: Forwarding Packets With Link Local Destination Addresses

Brian E Carpenter <brian.e.carpenter@gmail.com> Thu, 07 January 2021 20:02 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 1A0403A1053 for <ipv6@ietfa.amsl.com>; Thu, 7 Jan 2021 12:02:33 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.361
X-Spam-Level:
X-Spam-Status: No, score=-2.361 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=-0.262, 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 KpmIDB15xqEo for <ipv6@ietfa.amsl.com>; Thu, 7 Jan 2021 12:02:32 -0800 (PST)
Received: from mail-pg1-x530.google.com (mail-pg1-x530.google.com [IPv6:2607:f8b0:4864:20::530]) (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 BD5443A0D75 for <6man@ietf.org>; Thu, 7 Jan 2021 12:01:47 -0800 (PST)
Received: by mail-pg1-x530.google.com with SMTP id q7so3801500pgm.5 for <6man@ietf.org>; Thu, 07 Jan 2021 12:01:47 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=qpS5jxAaErfXVP0BI9RWEe11U6JMm4hIqKg2nCQpm20=; b=IQFuA5No2M/iAUKNw/i26Ln2ZfploDmYVhd9MQtOZ4rouj1P5UWFpAbrNPtOQuMmYd ED83JQHdi4ebRhoM0UuxlPOEn6OMMJDAs+RxySfSxs5x9YjLJRKbJIcBnkzbtKv6Tpjp qqXiYzw7vo+bgzac/dwVjJTYgEdhkMYYToTz5wuPVIaDTMgYUnAnBFg2SHIsWXxJvN7e DDaoQ7jfQA9iK+qFKi0pB5V4lLZ6fGkrli7h47MQvFkHuvdisC0ojPYPepUnqqOoAZws V9QR5uts0p34f84SaYi7TsyoHwbbJKYF41mIy2RTUX0m3qyAJmf4MG7oQvKXbrBolHzY NYDA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=qpS5jxAaErfXVP0BI9RWEe11U6JMm4hIqKg2nCQpm20=; b=D1HI+2py/XL+h2HKJs20FOGlqE6jJ5yUIaW5EUr8DBpEbtCVbxphShtZcyTHWfByj3 f28gLXrDh+Bbt5T1gpULiXvNLRtYZ2VGFqnOkpZTlYEqKRX/JVP8NTSAmyh/6gvwiUIh BMEezRxdWMalQbujXxwfSPkoEKNqGzsnerW5pIK7ayvy7U4NvtDz0F0hpZmlY5Ma2D2c 1npsdzcE5MtgPiHqgInCMYv4fRTmmvekwdjkzZMtm6hEaPv9j+MVVQkRhrk5FMxge6Gb fHPMlPziE9n8K5xXLJAndT8Z885tvn6VaNX5ExFxa9lbVyfkTPAKOBmxlIIICPd8R2ff fHzg==
X-Gm-Message-State: AOAM531e6ApxPlxn3JTrqvqT7LsKp4LVtTchCjVf8amqJp7nYyVvEnyQ nEr9nx2Lzo/j5WmODyc+XsnYziuv2I1ddQ==
X-Google-Smtp-Source: ABdhPJwmOPUxpRqhghCw//W8JY6K9dcWhXdraWXBrgPYjOvY50w2KbaRUYTnezDXVJoWRqPSqJ9dCg==
X-Received: by 2002:a63:5304:: with SMTP id h4mr3408469pgb.199.1610049706878; Thu, 07 Jan 2021 12:01:46 -0800 (PST)
Received: from [192.168.178.20] ([151.210.131.28]) by smtp.gmail.com with ESMTPSA id v6sm6503473pfi.31.2021.01.07.12.01.44 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Jan 2021 12:01:46 -0800 (PST)
Subject: Re: Forwarding Packets With Link Local Destination Addresses
To: Ron Bonica <rbonica=40juniper.net@dmarc.ietf.org>, "6man@ietf.org" <6man@ietf.org>
References: <DM6PR05MB6348A18046C5DDC7CF2AED76AEAF0@DM6PR05MB6348.namprd05.prod.outlook.com>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Message-ID: <13fc3aa3-458f-42e8-0fac-f2448a5beab3@gmail.com>
Date: Fri, 8 Jan 2021 09:01:43 +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: <DM6PR05MB6348A18046C5DDC7CF2AED76AEAF0@DM6PR05MB6348.namprd05.prod.outlook.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/rngOD_6JQySmqrA-HbOMZdaRvY8>
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: Thu, 07 Jan 2021 20:02:39 -0000

Ron,

On 08-Jan-21 06:53, Ron Bonica wrote:
> Folks,
>  
> According to RFC 4291, “routers must not forward any packets with Link-Local source or destination addresses to other links”.
>  
> I interpret this statement to include packets that contain routing headers. For example, it forbids an SRv6 packet whose final segment has a locator that begins with FE80.

As the discussion shows, you really should write "a locator that matches fe80::/10". With that fix:
 
> Does everyone share this interpretation? If so, do RFC 4291 or RFC 8200 make this sufficiently clear?

Yes, and the ensuing discussion about the metaphysics of scope is irrelevant.

    Brian