Re: [Doh] [Ext] Does the HTTP freshness lifetime need to match the TTL?

Martin Thomson <martin.thomson@gmail.com> Wed, 09 May 2018 00:22 UTC

Return-Path: <martin.thomson@gmail.com>
X-Original-To: doh@ietfa.amsl.com
Delivered-To: doh@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id ABBE112D7F7 for <doh@ietfa.amsl.com>; Tue, 8 May 2018 17:22:25 -0700 (PDT)
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 5Rtrx_-HBkTo for <doh@ietfa.amsl.com>; Tue, 8 May 2018 17:22:23 -0700 (PDT)
Received: from mail-ot0-x22c.google.com (mail-ot0-x22c.google.com [IPv6:2607:f8b0:4003:c0f::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 BB0DF12426E for <doh@ietf.org>; Tue, 8 May 2018 17:22:23 -0700 (PDT)
Received: by mail-ot0-x22c.google.com with SMTP id m11-v6so32030224otf.3 for <doh@ietf.org>; Tue, 08 May 2018 17:22:23 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ATFbr5OroE3m4YGvzc6CBo+yIPC66q+Aeba4usIIQNA=; b=uRdK52RnvbxpljnmqrtBxMGm6hHhWHroBFW9iH31PTqKitL5diVp68AlrDDPDLvvp0 W0ILcge1AdNtHaLAaJjQE27pZNlgGoAnSiZp6ZGqsLjqWeXuZ9Jp1iv0zDjqcQzkvRJ2 Wetv3jTDX18COlg8Jn6DQcZ6evpndUqyXtwWP+BwpjqUzvJ3fZKk/Vb5yTOvgsrkJpB+ VFk4229RHJRQHff1x4P8lUw3xY/Q4mYcEaXt8F1u49He1z1Qz2rf5wzqFxRxm7i0rA44 QhisbDfERsrzwaMf8b9Uii1EFhs5H+Px7usAwD+7V0qWVkkG49YPddnmxr7Lnwx0ZKw4 N5fA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ATFbr5OroE3m4YGvzc6CBo+yIPC66q+Aeba4usIIQNA=; b=iduspZbUI/sQx5uXdynQWK0ydudIDQu6pvPBczEp2FAzor3hL9fyYwal+z0r75xGhq Ac57YOJVfqzt7mar04B8r0zUzZhXjUxQ94sUqaF9idW3cB0Gi0VtSlBJmbh2Yqv4R8gy ZVi2a4DMy+ikbP52Oa3Woun9/FDuqUv5LoXabeUN6Kbc3CZRZxpAgfUItnezybTH7z+s 3+a2Qxp38omUchxYQMzCNJHt5Dke3yGcmJsF8zUvHkZIqLYtAPoqpOx5sFa4tHMLlWXz DYw/OeOTDoCTfHndCt16BGkgoTWNtQYbslHXGSkc2Mp1RoOjI9id/K2uWFLPhZeDZv/e p4xQ==
X-Gm-Message-State: ALQs6tDpNEo+LqgSFGnSq4D1ECO86w91FMnsEPF5JGyzk859AEFGxsYW hAHSbb/thllpvjWA1ZSThkxfnG39OR0o0tz7ibs=
X-Google-Smtp-Source: AB8JxZq5CzwpaGG7THSxP/GeOd8iLgPQaDr5ziKxEbg2JcnZda6TxDzYBNAvUcI4eXK6qcK/mmnnl1HmmZZBLvIG/zI=
X-Received: by 2002:a9d:72c6:: with SMTP id d6-v6mr17841373otk.392.1525825342950; Tue, 08 May 2018 17:22:22 -0700 (PDT)
MIME-Version: 1.0
References: <15A1809C-2CA3-4A3B-A5B1-279227C30223@icann.org> <3E34581E-E2DC-48B7-A4AD-6B9FDA418179@icann.org> <31900328-8813-47D3-9F89-0B863CE673B3@mnot.net> <CAOdDvNoQC=e8GTHU5Bw1KkR0r+dyKhqsVDRXvuyJb+jQSKn8GQ@mail.gmail.com>
In-Reply-To: <CAOdDvNoQC=e8GTHU5Bw1KkR0r+dyKhqsVDRXvuyJb+jQSKn8GQ@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
Date: Wed, 09 May 2018 00:22:12 +0000
Message-ID: <CABkgnnX-TJX2yTBaVbqiOrDrciyg=chKY8eNeBX2Lqy_Og8YyA@mail.gmail.com>
To: patrick mcmanus <pmcmanus@mozilla.com>
Cc: Mark Nottingham <mnot@mnot.net>, Paul Hoffman <paul.hoffman@icann.org>, DoH WG <doh@ietf.org>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <https://mailarchive.ietf.org/arch/msg/doh/8dBhJuFQw2jy8RkhkUw4UkJY3ks>
Subject: Re: [Doh] [Ext] Does the HTTP freshness lifetime need to match the TTL?
X-BeenThere: doh@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: DNS Over HTTPS <doh.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/doh>, <mailto:doh-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/doh/>
List-Post: <mailto:doh@ietf.org>
List-Help: <mailto:doh-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/doh>, <mailto:doh-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 09 May 2018 00:22:25 -0000

On Tue, May 8, 2018 at 9:37 PM Patrick McManus <pmcmanus@mozilla.com> wrote:
> Comments from you and Martin (and this text suggestion) support changing
this from normative language to advice. The other comments favor the more
deterministic behavior we currently have.

I'm just glad we're having the discussion.  There wasn't a lot of debate
about this point and now it seems like it's well-litigated.  (Beyond my
tolerance, but that's OK, I have a short attention span.)

In any case, Mark's text is an improvement; with or without the use of 2119
language.  I don't like having two sources for the same type of
information, but that is the nature of the protocol we're building.

I had hoped that we could lean more heavily on DNS, but it seems like DNS
folks want to lean more heavily on HTTP mechanisms.  That's something to
reflect on, perhaps, but not worth more debate.