there should be a ULA prefix?? [was: A common problem with SLAAC in "renumbering" scenarios]

Brian E Carpenter <brian.e.carpenter@gmail.com> Tue, 26 February 2019 19:35 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 C85F7128AFB for <ipv6@ietfa.amsl.com>; Tue, 26 Feb 2019 11:35:51 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2
X-Spam-Level:
X-Spam-Status: No, score=-2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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 MhKGoejg9VMX for <ipv6@ietfa.amsl.com>; Tue, 26 Feb 2019 11:35:50 -0800 (PST)
Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) (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 6C915126C01 for <ipv6@ietf.org>; Tue, 26 Feb 2019 11:35:50 -0800 (PST)
Received: by mail-pf1-x42d.google.com with SMTP id n74so6715774pfi.9 for <ipv6@ietf.org>; Tue, 26 Feb 2019 11:35:50 -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=zAjPsiXgWNc2gLXT3qdiZo6Sa4xoDiw5pS6ssKApdcs=; b=e/OY154ufShJ6k3V9h2gD1SFYzAu1CmmLLDAS5SYsv+ymAu6sAu5ck/PrXUNWb2l// v7TALl/SQVEQF8U/6Z0kqEKAfS0VJjQUSZT+WgiyS3tHOGbKfafaecs2TXNFpgHv1eSI a5SFFKMJ5Zbd8Smm2sJn1l1giuextVucT15IL4NBiWNhP7oas4oK/yKU7AtI+Fpu3epv DOwpYLsbVdSTXbFKypOdDNrCmcT5R30EFypz2my2/GTVZEgQ9jMCRKDM90Vsg75U1fBF iHRwyOmrB7zqZbpI4H6jQwY5FAkafBXhILXj3hYNU3yuyX1trkItrGGQtWbOlcXTZTHa v25w==
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=zAjPsiXgWNc2gLXT3qdiZo6Sa4xoDiw5pS6ssKApdcs=; b=mW4LFwBdROjTFSrQbtiUMrLSmq/Uumq7C4fjZR1JST1aMF/PmncdXIyPMsoSCrGu8q Upp1O5nND2KCaU2EH7Uo62EjFawXtit6mjKgkILrZ6J/wnjmIN5yTDNPq+bcniZHQYKU Bo/72q6QbZPWWktJDVRaI3cGD535xiLZ5q4dqqZpEDejp55o38+e+Ul8Or1IbNh/DvbD xKeIcLlc+uesuNGSi1CQSYHaTQi9CaYvBKx4SxDcusEG0cZwhM13X2sG6sjYXnKl4VWx zMa0k4MU9bPMueyB+ctlkpZFDt40H2Z84d1ToNRpLMEs5w3WXy2jlLhEb78mdr/z+q0s FpZg==
X-Gm-Message-State: AHQUAuYOzSSFkbQOMRdP9tNgWsLgO2cWZ5pepofr0z+LMjwYw1NjXVDv GgoHCgFF2Ngaamnj/mGMbYo0dl7y
X-Google-Smtp-Source: AHgI3IYAVvsV09jvWaemxgKuNJQXgMDDvq4a18d9lU4LyknkYbMedl/pWJErVEBxmtCK/p5Z4GKR/A==
X-Received: by 2002:a65:6383:: with SMTP id h3mr25517027pgv.11.1551209749564; Tue, 26 Feb 2019 11:35:49 -0800 (PST)
Received: from [192.168.178.30] ([118.148.79.176]) by smtp.gmail.com with ESMTPSA id l5sm7539095pfi.97.2019.02.26.11.35.47 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Feb 2019 11:35:48 -0800 (PST)
Subject: there should be a ULA prefix?? [was: A common problem with SLAAC in "renumbering" scenarios]
To: Philip Homburg <pch-ipv6-ietf-6@u-1.phicoh.com>, ipv6@ietf.org
References: <6D78F4B2-A30D-4562-AC21-E4D3DE019D90@consulintel.es> <019c552eb1624d348641d6930829fd1f@boeing.com> <CAKD1Yr0HBG+rhyFWg9zh0t3mW486Mjx9umjn+CRqAZg4z9r0dg@mail.gmail.com> <20190221073530.GT71606@Space.Net> <CAO42Z2wmB2W52b4MZ2h9sW5E9cQKm-HRjyf--q8C26jezS7LXQ@mail.gmail.com> <a73818d31db7422b99a524bc431b00ed@boeing.com> <CAO42Z2z9-48Gbb_Exf+oWUqDO=axSLpZBtqeDcxkAoFq5OziGw@mail.gmail.com> <CALx6S3624hnGauG1HaSWPMvQw0t2Q5R3gb8W4R8w3kuK7dcrWQ@mail.gmail.com> <1F07F2BB-2F37-4D12-9731-7892DF4E3D88@consulintel.es> <0a582916-af14-bd82-a4cd-002a36f8830b@huitema.net> <67515a73-26a5-3ed0-da88-1a4ce64550d3@foobar.org> <360afa02-cf23-375c-4876-780d3c2aa5ac@gont.com.ar> <CAHL_VyD34V=TRcsCp0DOO9HJNHyy5xkiMQ_cZoBa7zTE4fe5OA@mail.gmail.com> <ead01e0a-9211-7944-88d6-ae8d037c03a8@si6networks.com> <FB8B77EE-CC16-4418-BB5E-D44EE66D6B72@jisc.ac.uk> <29dcc6ed-03f6-3ead-6866-eecbefdf 1483@si6networks.com> <899A1249-D3D9-4824-8B2E-7E950FBB316A@jisc.ac.uk> <m1gya2p-0000HVC@stereo.hq.phicoh.net>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Message-ID: <9b7ba4df-41df-2c03-ddca-e15289075bff@gmail.com>
Date: Wed, 27 Feb 2019 08:35:48 +1300
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1
MIME-Version: 1.0
In-Reply-To: <m1gya2p-0000HVC@stereo.hq.phicoh.net>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/0ODf86ZMu5FV0XHyNUymneZbRAU>
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, 26 Feb 2019 19:35:52 -0000

Philip,

On 26-Feb-19 23:33, Philip Homburg wrote:
>> So given that document is 12 years old, with that default copied from one that
>> is 21 years old, is an update required?  
>>
>> And if so, to what?
> 
> I think this should be updated.
> 
> A long time ago, the model was that you would get a prefix from your ISP
> and that was the only global prefix on the local network.
> 
> So with short lifetimes, if the internet connection would go down for a 
> relatively long period, there would be no global prefix anymore and hosts
> would have to resort to link local to communicate (which obviously fails
> if there are multiple subnets).
> 
> Some time in the past, the thinking changed and now there should be a ULA
> prefix in addition to any global prefixes.

Really? Where do you think that is stated?

I happen to run my CPE with ULA enabled, but I'm not aware of any
recommendation to do so.

> So I think that with a ULA, it makes more sense for a CPE to limit lifetimes
> to some multiple of the RA interval.

Why? I don't expect my ULA prefix to change ever. Or do you mean the lifetimes
for globally routeable prefixes?

   Brian