Microloop protection as discussed in today's meeting
Stewart Bryant <stewart.bryant@gmail.com> Tue, 19 July 2016 15:12 UTC
Return-Path: <stewart.bryant@gmail.com>
X-Original-To: rtgwg@ietfa.amsl.com
Delivered-To: rtgwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 9731112D8D6 for <rtgwg@ietfa.amsl.com>; Tue, 19 Jul 2016 08:12:28 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.7
X-Spam-Level:
X-Spam-Status: No, score=-2.7 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_LOW=-0.7, 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 eH8Uq3W8rEma for <rtgwg@ietfa.amsl.com>; Tue, 19 Jul 2016 08:12:27 -0700 (PDT)
Received: from mail-lf0-x243.google.com (mail-lf0-x243.google.com [IPv6:2a00:1450:4010:c07::243]) (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 0AE2E12D81B for <rtgwg@ietf.org>; Tue, 19 Jul 2016 07:48:34 -0700 (PDT)
Received: by mail-lf0-x243.google.com with SMTP id f93so1515864lfi.0 for <rtgwg@ietf.org>; Tue, 19 Jul 2016 07:48:33 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:subject:to:cc:message-id:date:user-agent:mime-version :content-transfer-encoding; bh=YuUcCUNapk6MZupkUJoBFG54k7UMYjtogS6BWOGLY6k=; b=MYP2d9GKYEIg1uAUUtuUlJWX9vvOQ6IrLhPVF6dUAI3uRs70XJs4a1AcsMJ91pvSRc FLj1gS9aYASOQXJYpzjCb3M+nUbyZmkhvvfKUigIm+sJSBLGqr5Ej0RAG+Da9kkT80Nt M26f6l8A8d62irdcZg+5BYzv9KDjhBKcFEAABR1kI1g8qpVY5mrNPPqao4s+8+XOT0bw 46rJ7IwPinO5kmjVvAHFktPj7wdlecLHLTOh84eO56ymolfGUltROZSxwKuzHOi5iMba y97Zgyty+EgufQXBIvqULAe8tUXManAMQxsIGlu/3cw7qLCCnJpozsWQWdneLZu5IWcU cEDA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:subject:to:cc:message-id:date:user-agent :mime-version:content-transfer-encoding; bh=YuUcCUNapk6MZupkUJoBFG54k7UMYjtogS6BWOGLY6k=; b=cRmRlNZni5DsRHw1gG/I4oGgjybDAyCuV7AGTUmanm9YXm6++Uynz5FL4EMjwgDhx1 MS1/2d9hVkmqCItYpahO0jqqL/y0f/HxBrawicQtvlaJFhYTx/No7C/8MgLi5I6U/AD3 R8xdpeHFOasD6LWP7V2405MpoNb9ZVVRmpoqJV2UnWp6AHOkAp8lvSt2ejVwEAduhud4 EKTtE3zXUSFV6OBmqCUxDMvw3xjnupLzDHZNIyb0sBlBX8zkyoiZWEqZbxTXt+4kXWiG ixuNprgiJZWhyzAa4vHLDjVLCZGylUHQ570yH5a/c0riLYRXJ0ZwUI1SY7MRWtZtceW7 AW+w==
X-Gm-Message-State: ALyK8tIV9ms5lePgZnGOFiTcw1BoTggtf+6G3cEleMd/V7ZAN9yBI9c5xglHx/Hmis5JoQ==
X-Received: by 10.25.169.147 with SMTP id s141mr16792735lfe.203.1468939712024; Tue, 19 Jul 2016 07:48:32 -0700 (PDT)
Received: from ?IPv6:2001:67c:370:160:6df2:e046:d7b5:36d0? ([2001:67c:370:160:6df2:e046:d7b5:36d0]) by smtp.gmail.com with ESMTPSA id p102sm3999239lfi.9.2016.07.19.07.48.29 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 19 Jul 2016 07:48:30 -0700 (PDT)
From: Stewart Bryant <stewart.bryant@gmail.com>
Subject: Microloop protection as discussed in today's meeting
To: rtgwg@ietf.org
Message-ID: <578E3DBD.9030702@gmail.com>
Date: Tue, 19 Jul 2016 15:48:29 +0100
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2
MIME-Version: 1.0
Content-Type: text/plain; charset="windows-1252"; format="flowed"
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/rtgwg/dbOH9qAAvt22MiEV6FYaJYQWVKE>
X-BeenThere: rtgwg@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Routing Area Working Group <rtgwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtgwg>, <mailto:rtgwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/rtgwg/>
List-Post: <mailto:rtgwg@ietf.org>
List-Help: <mailto:rtgwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtgwg>, <mailto:rtgwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 19 Jul 2016 15:12:28 -0000
Appologies if this is a duplicate. The RFC that had all of the generic methods that were known at the time of publication is RFC5715. The two phase methods were in section 6.2 (near-side) and section 6.3 (far-side). The first describing tunnelling the traffic towards the repair (and continue to use the repair), the second describing tunnelling traffic towards the destination. For the purposes of this discussion source routing of all flavours can be considered a type of tunnel. If this approach is a new genetric two phase method, it would be useful to articulate it in general terms. The type of topology that I was trying to explain in the meeting is as follows A-B-C-D-E-F-H-I-J.....W | | | | +------X-Y-Z----------+ All costs are 1 and Y has failed. Traffic to Z can enter enywhere, and is protected by X. When the network starts to converge ALL the routers A..J will need to update their fib to forward towards Z via W rather than towards X via A. If they do this in a random order as would be the case without LF convergence then you may precipitate microlooping. What you need to do is to force the packets toward either X or Z using a tunnel, or a source routed path, and as far as I can see you need to do that at every point of potential entry into the network, in the above case A..J, else you risk a microloop. Now I suppose that if ALL packets were source routed, then you could consider that the network was constantly in the first phase, but I think that you would need to use strict source routing, rather than loose source routing else it reduces the the problem I describe above. - Stewart
- Re: Microloop protection as discussed in today's … Ahmed Bashandy (bashandy)
- Microloop protection as discussed in today's meet… Stewart Bryant
- Microloop protection as discussed in today's meet… Stewart Bryant
- Re: Microloop protection as discussed in today's … Stewart Bryant