Re: [v6ops] Happy eyeballs suggestions, was: Re: Apple and IPv6, a few clarifications

james woodyatt <jhw@nestlabs.com> Mon, 22 June 2015 21:26 UTC

Return-Path: <jhw@nestlabs.com>
X-Original-To: v6ops@ietfa.amsl.com
Delivered-To: v6ops@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 941FF1AD2C0 for <v6ops@ietfa.amsl.com>; Mon, 22 Jun 2015 14:26:55 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.001
X-Spam-Level:
X-Spam-Status: No, score=-2.001 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, SPF_PASS=-0.001] autolearn=ham
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 K_Pil1lRHFHk for <v6ops@ietfa.amsl.com>; Mon, 22 Jun 2015 14:26:54 -0700 (PDT)
Received: from mail-ig0-x22c.google.com (mail-ig0-x22c.google.com [IPv6:2607:f8b0:4001:c05::22c]) (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 D89311AC42D for <v6ops@ietf.org>; Mon, 22 Jun 2015 14:26:53 -0700 (PDT)
Received: by igbqq3 with SMTP id qq3so73791127igb.0 for <v6ops@ietf.org>; Mon, 22 Jun 2015 14:26:53 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nestlabs.com; s=google; h=content-type:mime-version:subject:from:in-reply-to:date :content-transfer-encoding:message-id:references:to; bh=m1VkqHc9DpdiZRRguiF3sOBBxCMWuC88UQj315C2qrE=; b=ZFiOdjv1UaUGfPUVx+muyOVO5mxWhx3+Z6nqftXLSA7kSVLyB3mBVtndk1woD+lgEM n2PiM7dl5whydhPXUUOJfT+nu4+/V5pBmlsvBz1277i4vpG1XfyM7jc5302A/3FfK130 Ben9oCjSdJPyGpn5lvsDHSuvYdBlYZqk699/8=
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:content-transfer-encoding:message-id:references:to; bh=m1VkqHc9DpdiZRRguiF3sOBBxCMWuC88UQj315C2qrE=; b=hdjzegpnDcdJUc6E5snnNxc0ooSIxVuV+kcmxOaGUDkYJG0FFGPcwzX9d2g51v4J0Y wPIYSKbCuRx6b7+Etyd8sK9IWAhQCxfezec/i9rDiqJX4ox5cf4tVjxc/dTybZnIgSCd 8uea9Ew7XiOLe9lj9G+Ebq3ZXhI/aADnZp9dhC8LTHBPc4N2yFHamKgPNRlkFk2R/WZW L5Jfsihu77kC3mTVML4MFiq7QZIQRuG49KTAIrBcVfjXXbk+JfZxWeVtN+Glx5pw7IPW jy5FD/ZazJfR8/oBbeq6rGTrsvU7HUR+pQgQ3GTidri7KdEzqoUsuU0QsksdGiLzCeqo OqsA==
X-Gm-Message-State: ALoCoQmMNk0WOTSxTfzbaRirn0YVKJIMy7cD9HiGO1WjhzFY7RWIQ0jLPRmOq6t2pkj7iYzEC87M
X-Received: by 10.107.138.87 with SMTP id m84mr41124178iod.80.1435008413264; Mon, 22 Jun 2015 14:26:53 -0700 (PDT)
Received: from ?IPv6:2620:15c:1:101:28f0:8c61:3c32:31cc? ([2620:15c:1:101:28f0:8c61:3c32:31cc]) by mx.google.com with ESMTPSA id 77sm13591273ioi.20.2015.06.22.14.26.52 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 22 Jun 2015 14:26:52 -0700 (PDT)
Content-Type: text/plain; charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2098\))
From: james woodyatt <jhw@nestlabs.com>
In-Reply-To: <1068D9DB-4300-473F-B511-880C1E9FB73D@muada.com>
Date: Mon, 22 Jun 2015 14:26:51 -0700
Content-Transfer-Encoding: quoted-printable
Message-Id: <78ABF014-6E93-40B8-8ABC-5BAF8AF96A47@nestlabs.com>
References: <E1C235B5-1421-4DAF-A2F3-F963982233DF@apple.com> <90744458-CA06-4347-A96B-D649800855D3@muada.com> <CAKC-DJhQ3kSPtkVHoPxtiUO-CbQkymehDF735nr8Q6=EUdUz0Q@mail.gmail.com> <1068D9DB-4300-473F-B511-880C1E9FB73D@muada.com>
To: Iljitsch van Beijnum <iljitsch@muada.com>, "v6ops@ietf.org" <v6ops@ietf.org>
X-Mailer: Apple Mail (2.2098)
Archived-At: <http://mailarchive.ietf.org/arch/msg/v6ops/YEvzcm4b6OqxYulOv3LWOkvjNUs>
Subject: Re: [v6ops] Happy eyeballs suggestions, was: Re: Apple and IPv6, a few clarifications
X-BeenThere: v6ops@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: v6ops discussion list <v6ops.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/v6ops>, <mailto:v6ops-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/v6ops/>
List-Post: <mailto:v6ops@ietf.org>
List-Help: <mailto:v6ops-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v6ops>, <mailto:v6ops-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 22 Jun 2015 21:26:55 -0000

On Jun 22, 2015, at 13:51, Iljitsch van Beijnum <iljitsch@muada.com> wrote:
> On 22 Jun 2015, at 18:53, Erik Nygren <erik+ietf@nygren.org> wrote:
> 
>> Having the NAT64/DNS64 environment is great for IPv6-only testing, but if it doesn't provide the ability to get through to real IPv6 content/resources when the MacOS host has IPv6 connectivity (either natively or via a tunnel) then it could be counter-productive in some circumstances and could discourage app writers from developing their apps to work well in scenarios where true end-to-end IPv6 connectivity is possible.
> 
> Hm, what kind of stuff would work through NAT64 that wouldn't work with real IPv6 connectivity?
> (Thinking of stuff that _would_ work with real IPv6 but not NAT64 is easier.)

An obvious example would be a UDP application that depends on a 1500 octet path MTU to all the IPv6 destinations it cares about. The NAT64 will shave a 1500 octet packet down to 1480, which might make it everywhere you want to go over IPv4 without needing to handle ICMPv6 Packet Too Big Errors, leaving you to discover later that native IPv6 destinations require you to deal with paths that are 1492 octets and not 1500 octets.

I’m sure if I think for a few minutes, I might be able to come up with another one. There are probably TCP cases like this too given the way ICMP6 filters seem to be so terribly popular despite the guidance our humble working group tries to provide.

—james