Re: [v6ops] What problem are we trying to solve? (Re: A broken promise - "You said PD Prefix Valid Lifetime is going to be X" (Re: SLAAC renum: Problem Statement & Operational workarounds))

Tassos Chatzithomaoglou <> Wed, 13 November 2019 07:33 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 91700120874 for <>; Tue, 12 Nov 2019 23:33:03 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.699
X-Spam-Status: No, score=-2.699 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (1024-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 2kbi1lzYBUc2 for <>; Tue, 12 Nov 2019 23:33:00 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 0244212022D for <>; Tue, 12 Nov 2019 23:32:59 -0800 (PST)
Received: from ( []) by (Postfix) with ESMTP id 6A4A1121C85 for <>; Wed, 13 Nov 2019 09:32:57 +0200 (EET)
Received: from localhost (localhost6.localdomain6 [IPv6:::1]) by (Postfix) with ESMTP id 658B812083C; Wed, 13 Nov 2019 09:32:57 +0200 (EET)
X-DSPAM-Result: Innocent
Authentication-Results: (amavisd-new); dkim=pass (1024-bit key)
Received: from ([IPv6:::1]) by localhost ( [IPv6:::1]) (amavisd-new, port 10032) with ESMTP id uqmEOZNhevrV; Wed, 13 Nov 2019 09:32:54 +0200 (EET)
Received: from localhost (localhost6.localdomain6 [IPv6:::1]) by (Postfix) with ESMTP id 63AE8120888; Wed, 13 Nov 2019 09:32:54 +0200 (EET)
DKIM-Filter: OpenDKIM Filter v2.9.2 63AE8120888
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=zm; t=1573630374; bh=mIHCDJmV9CU8NR5pXV2k/tQ/lEelvZjSoWrKi/IpMlA=; h=Subject:From:To:Message-ID:Date:MIME-Version:Content-Type: Content-Transfer-Encoding; b=W6Jiv8PaphnHu83wxHOINxTFcVHzJINc+u3HOlIeKiuqtgPt/cfIXjQ9d7U3aQw6I eWlR5GBK+bjUwv/zhz0sf0Bvqr+5pxuL/+fwfH3wXxSjD/YdHg0utsyyOLz9nlPkbZ B8f47MSOGIzVjfnLEVxJZmLoXlwUB9N6iDJBD5+c=
X-Virus-Scanned: amavisd-new at
Received: from ([IPv6:::1]) by localhost ( [IPv6:::1]) (amavisd-new, port 10026) with ESMTP id ZLmYfXGZLwUz; Wed, 13 Nov 2019 09:32:54 +0200 (EET)
Received: from [IPv6:2a02:2149:8769:2d00:e063:ae13:1d9c:d56e] (unknown [IPv6:2a02:2149:8769:2d00:e063:ae13:1d9c:d56e]) by (Postfix) with ESMTPA id 36C73120886; Wed, 13 Nov 2019 09:32:54 +0200 (EET)
References: <> <> <> <> <> <> <> <> <>
From: Tassos Chatzithomaoglou <>
Openpgp: preference=signencrypt
Autocrypt:; keydata= mQENBFPWrY4BCADa9txOlMMGA1PvelU2qfkJ3cIoF+M9wXhSvZTI63FfgZAMWVM/NryJQ74q kiaWFyprgqo2BBk6vWkCw0N8pVwx0Z0sbPisB1fo/zB29cyM0HeB8lnu+Z5AvkfjwekMtGJd 3+tsRwOqdAJpCpJNhS0cVAkk1lIe3i8pdBbbKYJ5VNpBTyi0zL18WRvz9qf8nnP50rQOF8Oc LNCyKrT5S02SonWH5fQDTMVaSDVRvzRLU34pL0WEsIfTQciwg9LhjRpGj6mHxX1OdRHBpHmH WAI05lg7xRwYZq2/X/9Xizd0j9hbr6Ph7oiW7u6e4zAndvPSxXaBVCzpVI0hhaJl11yVABEB AAG0G1Rhc3NvcyA8Y2hhdGFzb3NAeWFob28uY29tPokBPwQTAQIAKQUCU9atjgIbIwUJCWYB gAcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEG9JgN4loaV7D0kIAKfyVLWFzOfYM0uT m78iJsh9nAaxYiM0t40oF+HY7Cri35FDAzrRjbB0os/KehCz6uuBqDe+3swkVX9bwE9/GsHc Tb5C1IOdvgb2Rp3MfSF1+Ju/3uGtiktQIqZ5YrIZhIjGiwUCVC6ewpC3VRiFVo/HvE23p16y 6Ws9y4xoRNuxs0952twZjT9jwVub8TWm/uES6RERZ68FGA1jVFXtAgMXljP29KcL8zRw9xiY VNI1MgUIRhOKENzpChS+7jZSDWKKD9fwPUNDNPG9kNuXoinRX1g2wlgWKmaBNVBOZMunR20P eVewZ2v35uaiHyzzHw92vjjfxOtpXoW0QFlT5cg=
To: v6ops list <>
Message-ID: <>
Date: Wed, 13 Nov 2019 09:32:49 +0200
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Firefox/52.0 SeaMonkey/2.49.5
MIME-Version: 1.0
In-Reply-To: <>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Archived-At: <>
Subject: Re: [v6ops] What problem are we trying to solve? (Re: A broken promise - "You said PD Prefix Valid Lifetime is going to be X" (Re: SLAAC renum: Problem Statement & Operational workarounds))
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: v6ops discussion list <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Wed, 13 Nov 2019 07:33:03 -0000

Mark Smith wrote on 13/11/19 00:28:
> On Wed, 13 Nov 2019 at 08:20, Tassos Chatzithomaoglou
> <> wrote:
>> Fernando Gont wrote on 12/11/19 16:33:
>>> On 12/11/19 04:11, Tassos Chatzithomaoglou wrote:
>>>> The subscriber should have the choice to decide and the technology should give the means to support his/her choices.
>>>> We're building a page inside our subscriber portal, where the subscriber chooses how frequently the LAN IPv6 assigned prefix should change.
>>>> Default is to change at every PPP reconnect, but the subscriber can choose specific periods (x weeks/months) or action (once at next reconnect).
>>> So, upon a CPE crash and reboot, the subscriber would get a different
>>> prefix. Right?
>>> Thanks!
>>> Cheers,
>> Yes, the current default is for the subscriber to get a different prefix after a CPE crash and reboot (like in IPv4).
> "like in IPv4"
> Why are you giving customers delegated IPv6 prefixes - that's not like IPv4?
Between ULA+NAT66 and PD we chose PD due to CPEs supporting it by default (and following the end-to-end connectivity principle).
> Other than "like in IPv4", why are you making the PD prefix change
> upon reconnect when you don't have to?
We do the same in IPv4 because many subscribers had asked for it. They wanted to easily (disconnect the line or reboot the CPE) change addresses.
> What if your competitors provide stable prefixes, and their customers
> get a better service experience than your customers do, without having
> to wait possibly years for CPE and/or host upgrades per this ID's
> proposal?
> What is stopping them doing that? If they already have stable prefix
> supporting infrastructure, why wouldn't they switch it on when they
> can, when it could mean stealing customers from you and reducing their
> numbers of helpdesk calls?
That's mostly a commercial decision. Commercially we want to differentiate static vs dynamic.
The biggest technical issue i see is routing de-aggregation due to many different BRAS serving the same customers.
Aggregating at another level is not an option, because we don't want to have hundreds of thousands of /56s at this level.

Note: Largest percentage of our IPv6 related helpdesk calls is about DS-Lite subscribers having problems using a service requiring port forwarding (and their CPE doesn't support PCP), which we then change to the default Dual-Stack.

>> But a CPE crash is not a common case. The most common case for prefix change is a DSL disconnect (due to line issues) or a PPP disconnect (due to network issues).
>> Also, many of our CPEs store internally the prefix, so after a PPP reconnect they inform the LAN hosts about its release.
>> --
>> Tassos
>> _______________________________________________
>> v6ops mailing list