IETF Logo Mail Archive

Re: Exercising Version Negotiation

Ryan Hamilton <rch@google.com> Fri, 23 March 2018 20:19 UTC

Return-Path: <rch@google.com>
X-Original-To: quic@ietfa.amsl.com
Delivered-To: quic@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 15C1912DA3E for <quic@ietfa.amsl.com>; Fri, 23 Mar 2018 13:19:24 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.009
X-Spam-Level:
X-Spam-Status: No, score=-2.009 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, T_RP_MATCHES_RCVD=-0.01, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=google.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 CTkDSkVYdE6c for <quic@ietfa.amsl.com>; Fri, 23 Mar 2018 13:19:22 -0700 (PDT)
Received: from mail-yb0-x234.google.com (mail-yb0-x234.google.com [IPv6:2607:f8b0:4002:c09::234]) (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 AEB12126DC2 for <quic@ietf.org>; Fri, 23 Mar 2018 13:19:22 -0700 (PDT)
Received: by mail-yb0-x234.google.com with SMTP id o197-v6so3197112ybg.5 for <quic@ietf.org>; Fri, 23 Mar 2018 13:19:22 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=FMnttGWPOQx1+1TSRCGDJucqG3d0+ouUWcMmrhK9Az0=; b=CwfQNcd+Q16t0Rn7bjKFqN7IA5w52gm+jIWrsgFRiZtOrw2geDrUo/9rxpQS4M73+E rukgowiBkXw9201TJbdldvmWZenjoqzNzR3XJErxqXN1DuuJzOyRAiDIS4EYU03CNFqV dXCwBsrYHbXgAcfzGHoQmMNrDqosoWFLXvXsu3XNKW1Yv6//HXO6KAhAS4IZVO0+lxYk zf7f++qF/6Elyew4koEFrTyuLq/EHpf7Vt+CvpHEcr3finC6okzOSXJRjSBu45iIUhN9 0SfYmFSZIDAzzuJWZ4eiU2x7ltnjY5jZ9pDA0Fj0rC07wgLdI4lY+OR6zO3LVKDFiGde UlDQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=FMnttGWPOQx1+1TSRCGDJucqG3d0+ouUWcMmrhK9Az0=; b=kArrzlAiKdyHOLbOvJveyAhmr36smxRuXKCg6LxkjGDeTZmovVR6lSA068WmOun3Z3 7+YFSfxvJmWZpNpjTOOn5cFGhM/2mcvs/39FG1IV/vC4HuTutTNrN/G5cQlhjV62nRew AHmydquvDrw/mjjb6qMAGYHcny+cVnP+jgrJRlQVk/ZlvS4hlqzAm8rm2Xsevjrc723a FVt0v1BpazBf6j0l0ZrMLqvASaTb5EdyGBiYfPNT5aayxjqb3jY4AmH6CrY0xFEpf2IZ AV6GUwg+oZ5gEO9bZkLTpDOSmT973IA+kOaV9H6TQRdSABxvAfXSdZSdANK6QISiXZjG wQ0w==
X-Gm-Message-State: AElRT7Huze8r3A0N4g2uxg0QKXgCpD7rlTaw58dlwtalw6vn2Gg3hO9x JXxeRYLy9+J1TNN1Hcw0y4bkQBfLgHS7nQyLjcB16EwGFn0=
X-Google-Smtp-Source: AG47ELs0JRy/M2rAxu0UKzY89Wk/wnRJYHe1W9wZV0hkcAYytR/ho33kXWhQ01uD2AT0JrpBgztP29gz/yZIoy5jUvQ=
X-Received: by 2002:a25:744:: with SMTP id 65-v6mr16374663ybh.247.1521836361361; Fri, 23 Mar 2018 13:19:21 -0700 (PDT)
MIME-Version: 1.0
Received: by 2002:a25:98c5:0:0:0:0:0 with HTTP; Fri, 23 Mar 2018 13:19:20 -0700 (PDT)
In-Reply-To: <CABcZeBNfw6MjjgeqQct11g6Kf=4xy+zVZiBRMwwzhtKB2rWHZg@mail.gmail.com>
References: <CABcZeBMv5BqZOtgVA2wfqaaGCd94gcNPB9bTXkrvNXXRveU8wA@mail.gmail.com> <CAJ_4DfQ6zqVeUUF7XcoT110kVcP1BJFEtqVR-+FN5XD2UuRMMA@mail.gmail.com> <CABcZeBMVNy151rFntLutSPtctPsd2Ei3Qy-ChuEXVMVpz4pgdQ@mail.gmail.com> <SN1PR08MB1854DD71FDCB9FBA48DD26E9DAA90@SN1PR08MB1854.namprd08.prod.outlook.com> <CAJ_4DfQxcxNGNP9CW3poPqnFgUsrNy269dO2Lf0dvWBFKKsSHg@mail.gmail.com> <CABcZeBNfw6MjjgeqQct11g6Kf=4xy+zVZiBRMwwzhtKB2rWHZg@mail.gmail.com>
From: Ryan Hamilton <rch@google.com>
Date: Fri, 23 Mar 2018 13:19:20 -0700
Message-ID: <CAJ_4DfRCNRHajNfFdedg6O54mjydWt+ooRESJZQ5L0sZmcwmXg@mail.gmail.com>
Subject: Re: Exercising Version Negotiation
To: Eric Rescorla <ekr@rtfm.com>
Cc: Mike Bishop <mbishop@evequefou.be>, IETF QUIC WG <quic@ietf.org>
Content-Type: multipart/alternative; boundary="000000000000baaa4405681a2316"
Archived-At: <https://mailarchive.ietf.org/arch/msg/quic/72i6pITs25aou47SYlxtGGhLhM0>
X-BeenThere: quic@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: Main mailing list of the IETF QUIC working group <quic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/quic>, <mailto:quic-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/quic/>
List-Post: <mailto:quic@ietf.org>
List-Help: <mailto:quic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/quic>, <mailto:quic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 23 Mar 2018 20:19:24 -0000

On Fri, Mar 23, 2018 at 1:48 AM, Eric Rescorla <ekr@rtfm.com> wrote:

> On Thu, Mar 22, 2018 at 8:53 PM, Ryan Hamilton <rch@google.com> wrote:
>
>> Agreed. As specified, I don't see how the server would be induced to send
>> a version negotiation packet in this case. Ekr, perhaps you can provide
>> some sample flows. If the server supports versions A and B, and the client
>> supports versions A and B, then it doesn't matter which version the client
>> prefers. In either case, the server supports the version the client is
>> attempting to speak and will not send a version negotiation packet.
>>
>
> I'm not suggesting that you flip the preferences, but rather that the each
> side configure itself with one version for a given connection. This is
> obviously trivial for a client. For the server, you can just hash the
> client's IP address to get a stable choice.
>

​Ah, I misunderstood what you meant by, "We would then suggest to people
that they somewhat randomize their preferences (e.g., 99% of the time
prefer v1+i, 1% of the time prefer v1-i)."

How would you envision this working with Alt-Svc advertisements? Would the
server advertise support for both versions but only support a single one,
or would it advertise only the single version?

v2.46.0 | Report a Bug | By Email | System Status