Re: [trill] Explaining three options for upgrading to FGL (fine-grained-labeling)
Radia Perlman <radiaperlman@gmail.com> Thu, 31 January 2013 20:24 UTC
Return-Path: <radiaperlman@gmail.com>
X-Original-To: trill@ietfa.amsl.com
Delivered-To: trill@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 2D6A721F86EF for <trill@ietfa.amsl.com>; Thu, 31 Jan 2013 12:24:23 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Level:
X-Spam-Status: No, score=-1.999 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, HTML_MESSAGE=0.001, J_CHICKENPOX_31=0.6, NO_RELAYS=-0.001]
Received: from mail.ietf.org ([64.170.98.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id W5PdanWjltep for <trill@ietfa.amsl.com>; Thu, 31 Jan 2013 12:24:22 -0800 (PST)
Received: from mail-la0-x230.google.com (mail-la0-x230.google.com [IPv6:2a00:1450:4010:c03::230]) by ietfa.amsl.com (Postfix) with ESMTP id D952C21F86A9 for <trill@ietf.org>; Thu, 31 Jan 2013 12:24:21 -0800 (PST)
Received: by mail-la0-f48.google.com with SMTP id fq13so2231226lab.21 for <trill@ietf.org>; Thu, 31 Jan 2013 12:24:20 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; bh=w8uMzQ05F2vCeSTyjtJvAymV8O1FC5lE+1foBZx/7OA=; b=s6N/OjCEkZ3kDTNffv+FzeHc4xogs9wbgwaEM6oKNXZv17K5jaL91nnZ5L94HP2SJB Lmv5b+qFlXv3RVwYkk4acYl0IsaFTuN/H38EnB3srRK0xw112FSc7L7Qp5g5jLSJjK2T GuUb1/Z7LxWLCqxp2fUrxyNKcFATqHNgnaC+xKz33yuHYPhGgKACri7MKVrYQIltfpGG ttRY56I9zuOQFxOctQcWtKWdwGlh7SzcozgSObuy7S5jp5YX4+gqk/U1UvS2TbBoaOjp O2AtTSwVIEujBudnh8azeipU+LBBEhiEdWaxEgSHtJ9vYrtiZPXRPDRMUMoCYu51xu7A oTnw==
MIME-Version: 1.0
X-Received: by 10.112.50.109 with SMTP id b13mr3847353lbo.8.1359663860409; Thu, 31 Jan 2013 12:24:20 -0800 (PST)
Received: by 10.112.64.17 with HTTP; Thu, 31 Jan 2013 12:24:20 -0800 (PST)
In-Reply-To: <FBEA3E19AA24F847BA3AE74E2FE19356288F6978@xmb-rcd-x08.cisco.com>
References: <CAFOuuo67iBR2JkDtwPFCkrKHs3Fp4U_L1jkmNz5sfht6y05YMw@mail.gmail.com> <CA+-tSzx0E3J4i5Dvfbj4egruCeGi7z1se1Jn5RXtx3RedQLPdg@mail.gmail.com> <CAHD03N89RNX4=XxRZpD+Y2PCktYf-FtVjyYJ5oFS3dui3SsXaA@mail.gmail.com> <CAF4+nEG7YKGzGmObAMaOxackivjJsALymqHX=6PKBd5qU-Z+zQ@mail.gmail.com> <CA+-tSzz0=oh6iB1e-ESyeOx2sCvBFXeVpzuNbKmUVhRNLScDgQ@mail.gmail.com> <CAF4+nEFLrJL=CgX9e6on-cgz89ugmu93P6u5kmODhUia3H7RLg@mail.gmail.com> <1F5A81AE-4B3C-45FD-B431-9BA0011EB085@gmail.com> <DC8898F8-75C0-4535-BA61-C54279901332@gmail.com> <43DF00BE-B5F6-48B9-B313-8D179354C7B7@gmail.com> <A9B8F2D5-C3D7-4688-A76D-ED19EC47E59F@gmail.com> <FBEA3E19AA24F847BA3AE74E2FE19356288F6978@xmb-rcd-x08.cisco.com>
Date: Thu, 31 Jan 2013 12:24:20 -0800
Message-ID: <CAFOuuo4jZMdvUU_2EzBj1MLp6k0e+AmW1+k1ai4Q_m4rA0ObMw@mail.gmail.com>
From: Radia Perlman <radiaperlman@gmail.com>
To: "Tissa Senevirathne (tsenevir)" <tsenevir@cisco.com>
Content-Type: multipart/alternative; boundary="f46d0401fbc969e57604d49b6943"
Cc: Anoop Ghanwani <anoop@alumni.duke.edu>, Ayan Banerjee <ayabaner@gmail.com>, Sam Aldrin <aldrin.ietf@gmail.com>, "trill@ietf.org" <trill@ietf.org>, Donald Eastlake <d3e3e3@gmail.com>, Jon Hudson <jon.hudson@gmail.com>
Subject: Re: [trill] Explaining three options for upgrading to FGL (fine-grained-labeling)
X-BeenThere: trill@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: "Developing a hybrid router/bridge." <trill.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/trill>, <mailto:trill-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/trill>
List-Post: <mailto:trill@ietf.org>
List-Help: <mailto:trill-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/trill>, <mailto:trill-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 31 Jan 2013 20:24:23 -0000
Tissa said: >> how can you make sure all of the so called "Safe FGL" have consistent behavior "Safe FGL" need not all have the *same* behavior as each other...they just have to do "nothing bad" with an FGL frame. It's worth summarizing (again) what it means to be "FGL-safe", which allows you to coexist safely with FGL frames. To be FGL-safe you must do the following: a) unicast: you MUST NOT drop a packet because of seeing the unrecognized FGL tag. You also MUST NOT get confused and do flow hashing improperly (choosing different paths for packets for the same flow). b) multicast pruning: it's OK not to do pruning at all, or to actually look at all 24 bits of the FGL and prune as a proper FGL guy would do. But an example of what you canNOT do is look at the first 12 bits of FGL, pretend it's the same as VL, and delete the multicast packet because nobody downstream is listening to that 12 bit VL value c) egress of either unicast or multicast: you MUST NOT egress an FGL frame onto a link that is not supposed to get that FGL value d) you have to advertise that you are FGL-safe...otherwise other RBs will assume you are VL ("FGL-unsafe") --------- Also, TIssa said: >>Do you agree if we say, FGL will always be core of the network, and VL will be at the edge of the network ? With option 2, a VL guy *cannot even be at the edge of a network with FGL links* unless it is upgraded to FGL-safe AND advertises that it is FGL-safe. Option 2 says a VL guy is completely ostrasized once FGL-labeled links are introduced. There is NO coexistence of VL guys and FGL-links. The only kinds of coexistence in option 2 are: a) VL and FGL-safe RBridge, but no actual FGL links yet. b) FGL-safe guys, even if some of them don't really understand FGL, but just don't do "anything bad" with it, and FGL frames. So...again...the migration phases in option 2 are 1) VL-only (today's deployment), then 2) A mixture of VL and FGL-safe, until 3) EVERYone upgraded to FGL-safe, then 4) FGL-links can be introduced. ---- Also, Tissa said: >>what about some devices who are not "safe FGL" and so on, are we saying do not buy no safe FGL devices, if you do that you cannot get FGL interop ? *If* it's important to have VL guys as transit, and they cannot be upgraded to FGL-safe because upgrading requires a hardware change (it involves parsing data packets), then we are stuck with option 3. In option 3, we can forever have VL guys at the edge speaking through an FGL-safe or full-FGL core. In option 2, as I said, there is *no coexistence* of VL guys, *even at the edg*e, once FGL links are introduced. In option 2, a VL guy, even at the edge, will be ostrasized completely once anyone advertises connectivity to an FGL link. I personally like option 2, because it's simple, but as Einstein said "make things as simple as possible, but no simpler". We have to make sure that everyone understands the implications of option 2, and can live with them. To summarize again (since there seems to be some confusion about what the implications of option 2 are), If we can upgrade all existing VL implementations to FGL-safe through software upgrade only, then option 2 provides smooth migration by changing ALL RBridges (edge as well as transit) to FGL-safe, and only after ALL of them are upgraded, then FGL-labeled links can be introduced. If there are any remaining VL guys once FGL-labeled links are introduced, the VL guys are ostrasized, *even if they are just at the edge.* If we canNOT upgrade all existing VL to FGL-safe, AND if it's important to be able to mix VL guys into a network with FGL frames (say, having VL guys at the edge), then option 3 allows this. So hopefully everyone understands the implications of option 2 fully before voting. As I said, I don't know about whether there are VL chips that would require a hardware upgrade to become FGL-safe. Assuming there are none, then I'm quite happy with option 2. And actually, it looks like people are converging on option 2 (though I hope it's based on fully understanding option 2). Now is the time for people to speak up, that know of problems this would cause...for instance, needing to have non-upgradable VL guys at the edge for a long time. Radia
- [trill] Explaining three options for upgrading to… Radia Perlman
- [trill] 答复: Explaining three options for upgradin… Haoweiguo
- Re: [trill] 答复: Explaining three options for upgr… Radia Perlman
- [trill] 答复: 答复: Explaining three options for upgr… Haoweiguo
- Re: [trill] Explaining three options for upgradin… Anoop Ghanwani
- Re: [trill] Explaining three options for upgradin… Donald Eastlake
- Re: [trill] 答复: 答复: Explaining three options for … Donald Eastlake
- Re: [trill] Explaining three options for upgradin… Ayan Banerjee
- Re: [trill] Explaining three options for upgradin… Donald Eastlake
- Re: [trill] Explaining three options for upgradin… Ayan Banerjee
- Re: [trill] Explaining three options for upgradin… Anoop Ghanwani
- Re: [trill] Explaining three options for upgradin… Donald Eastlake
- Re: [trill] Explaining three options for upgradin… Ayan Banerjee
- Re: [trill] Explaining three options for upgradin… Donald Eastlake
- [trill] 答复: 答复: 答复: Explaining three options for … Haoweiguo
- Re: [trill] Explaining three options for upgradin… Yizhou Li
- Re: [trill] Explaining three options for upgradin… Tal Mizrahi
- Re: [trill] Explaining three options for upgradin… hu.fangwei
- Re: [trill] Explaining three options for upgradin… zhai.hongjun
- Re: [trill] Explaining three options for upgradin… Sam Aldrin
- Re: [trill] Explaining three options for upgradin… Linda Dunbar
- Re: [trill] Explaining three options for upgradin… Jon Hudson
- Re: [trill] Explaining three options for upgradin… Sam Aldrin
- Re: [trill] Explaining three options for upgradin… Jon Hudson
- Re: [trill] Explaining three options for upgradin… Sam Aldrin
- Re: [trill] Explaining three options for upgradin… Tissa Senevirathne (tsenevir)
- Re: [trill] Explaining three options for upgradin… Radia Perlman
- Re: [trill] Explaining three options for upgradin… Olen Stokes
- Re: [trill] Explaining three options for upgradin… Radia Perlman
- [trill] 答复: Explaining three options for upgradin… Haoweiguo
- Re: [trill] 答复: Explaining three options for upgr… Radia Perlman
- [trill] 答复: 答复: Explaining three options for upgr… Haoweiguo
- Re: [trill] Explaining three options for upgradin… Jon Hudson