Re: [v6ops] 464xlat case study (was reclassify 464XLAT as standard instead of info)

james woodyatt <> Tue, 26 September 2017 21:59 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 9E25F134499 for <>; Tue, 26 Sep 2017 14:59:31 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Status: No, score=-1.999 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id EJPbNISt_gta for <>; Tue, 26 Sep 2017 14:59:29 -0700 (PDT)
Received: from ( [IPv6:2607:f8b0:400e:c05::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id B08D5134493 for <>; Tue, 26 Sep 2017 14:59:29 -0700 (PDT)
Received: by with SMTP id c137so6639117pga.11 for <>; Tue, 26 Sep 2017 14:59:29 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=wvBazr2Hl43hlJ+S8xeL/6n9nM0yqTgyfuwKaAkMoO4=; b=aF/39IYsTwXC9yGA8kwkIsfbdofhBf4RWYF5G7+4bT6bbQYO24gdaSXvTjMCphaqWK 62DUbCPOTfzAw34BuO+0Zx4WYiz9WNvgr+q0rOc+DbZUsR0NGL9GxufuzaBekVqxEdCX pFyDI7KnCKavYx9Ju6s1Mb2EaDl5PmPjTNwm+Gr26g48YWCPRAAFAHYGvnJaeFw5l/Ay metfq7tRFluyekYXVclSeZfVNlVhFYSVQKJ7MRN2XR4cJHKv4tyhqKdOC7uY9gTC5Ux1 ds+mZWvnAvwnoDIQkBnAiT2+3gkC3+nVAnbz5O3bBpa/3YJoNX+JjpW4XCmJbcdKLAxK UalQ==
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=wvBazr2Hl43hlJ+S8xeL/6n9nM0yqTgyfuwKaAkMoO4=; b=JP7M19cVijSq3KbcnBckCursfwR9bhI0RTButkS0f4wUZpTcay/4DmzKOdmhFnMlP5 049nfdiBNsEOivCEKBD5u0ShuY0admRiOiR9bodYSHfc46VizgrzIZhDlKExDTVRgZvH GGDmLeC3KB97efSRVDDglUmlCKU50cFP03lBvAk1QIw7XVX9es2M7fVbd5mEPD+IxkEI Pc18MnZLIms8zQEcHMQOv25nxiYgBO7ObYelFP8yOZrqNXnSEigpaqcS6lWyVsfIadqG VgjFW7Reu98zU/WjPXTqKyB+ZCk+QPfn+HF4y+lLtIq/KSILXKOwzNZhAbJz7jNsdNdO GKBQ==
X-Gm-Message-State: AHPjjUh3Q6J1Lx4HQ775M2CKEezTCN85KesHgATMSuhaIAOpxYsZ28cb 57juizGiy6T9rPncHPpPZmvVog==
X-Google-Smtp-Source: AOwi7QDzsePJ1YzUyXYjxNIX0cJ+5/Pu52g+mjIJ80u9pNDYwULu0OmTUuTsRzZGd2+n5qKNXkGrfg==
X-Received: by with SMTP id e6mr5391069plk.46.1506463169003; Tue, 26 Sep 2017 14:59:29 -0700 (PDT)
Received: from ?IPv6:2620::10e7:10:916e:c73b:d1cf:8010? ([2620:0:10e7:10:916e:c73b:d1cf:8010]) by with ESMTPSA id i84sm17313630pfj.105.2017. (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Sep 2017 14:59:28 -0700 (PDT)
From: james woodyatt <>
Message-Id: <>
Content-Type: multipart/alternative; boundary="Apple-Mail=_85B1F795-CB45-4314-986D-165D2D8628DA"
Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\))
Date: Tue, 26 Sep 2017 14:59:27 -0700
In-Reply-To: <LO1P123MB01168388285206BB7C26F029EA7A0@LO1P123MB0116.GBRP123.PROD.OUTLOOK.COM>
Cc: IPv6 Ops WG <>
To: "Heatley,N,Nick,TQB R" <>
References: <LO1P123MB01168388285206BB7C26F029EA7A0@LO1P123MB0116.GBRP123.PROD.OUTLOOK.COM>
X-Mailer: Apple Mail (2.3273)
Archived-At: <>
Subject: Re: [v6ops] 464xlat case study (was reclassify 464XLAT as standard instead of info)
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: v6ops discussion list <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Tue, 26 Sep 2017 21:59:32 -0000

On Sep 25, 2017, at 04:56, Heatley,N,Nick,TQB R <> wrote:
> So this is my opinion: 464xlat is the currently the adopted approach when:
> - IPv4 addresses are (near) exhausted for the mass-market, 
> - AND the provider network demands a translation technology (i.e. incompatible with encaps.)
> - AND at the client end,  apps are not purged of IPv4 literals OR tethering to an unknown OS is required

For the first two bullet items and the second half of the third bullet item, you only need NAT64+DNS64, not the whole of 464XLAT.

You only put the CLAT on the handset for one thing, and one thing only: dealing with applications that still use IPv4 literals, and it’s not the only way to skin that cat, c.f. the approach used by Apple, which uses a bump-in-the-stack at a higher layer of the operating system instead of using the CLAT according to 464XLAT. It works fine in all the cases anyone really cares about, and when the apps that still use IPv4 literals are all retired from service, it won’ t be necessary ever again.

--james woodyatt < <>>