Re: [Isis-wg] Comments on draft-xu-isis-flooding-reduction-in-msdc-00

Hannes Gredler <hannes@gredler.at> Wed, 26 April 2017 00:54 UTC

Return-Path: <hannes@gredler.at>
X-Original-To: isis-wg@ietfa.amsl.com
Delivered-To: isis-wg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D14EA1317C2 for <isis-wg@ietfa.amsl.com>; Tue, 25 Apr 2017 17:54:57 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RP_MATCHES_RCVD=-0.001] autolearn=ham autolearn_force=no
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 2M85r_c4Okx0 for <isis-wg@ietfa.amsl.com>; Tue, 25 Apr 2017 17:54:56 -0700 (PDT)
Received: from gilfert.gredler.at (gilfert.gredler.at [87.106.222.165]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 68F761205D3 for <isis-wg@ietf.org>; Tue, 25 Apr 2017 17:54:56 -0700 (PDT)
Received: from hannes-mba.local ([::ffff:216.9.110.15]) (AUTH: PLAIN hannes, SSL: TLSv1/SSLv3,128bits,AES128-SHA) by gilfert.gredler.at with ESMTPSA; Wed, 26 Apr 2017 02:54:53 +0200 id 00000000035C43D4.0000000058FFEFDD.0000612E
To: Erik Auerswald <auerswald@fg-networking.de>, Xuxiaohu <xuxiaohu@huawei.com>
References: <20170418192723.GB17787@fg-networking.de> <1FEE3F8F5CCDE64C9A8E8F4AD27C19EE2BB93B83@NKGEML515-MBS.china.huawei.com> <20170425102617.GA22368@fg-networking.de>
Cc: "isis-wg@ietf.org" <isis-wg@ietf.org>
From: Hannes Gredler <hannes@gredler.at>
Message-ID: <44be93dd-92c4-e750-063a-b58867ec0dad@gredler.at>
Date: Wed, 26 Apr 2017 02:54:23 +0200
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:45.0) Gecko/20100101 Thunderbird/45.8.0
MIME-Version: 1.0
In-Reply-To: <20170425102617.GA22368@fg-networking.de>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/isis-wg/lm0WbMxQLTgwAocpDmG8rq8sqWY>
Subject: Re: [Isis-wg] Comments on draft-xu-isis-flooding-reduction-in-msdc-00
X-BeenThere: isis-wg@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: IETF IS-IS working group <isis-wg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/isis-wg>, <mailto:isis-wg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/isis-wg/>
List-Post: <mailto:isis-wg@ietf.org>
List-Help: <mailto:isis-wg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/isis-wg>, <mailto:isis-wg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 26 Apr 2017 00:54:58 -0000

+1

i'd like to add to erik's observations that mesh-group support is
available in contemporary router software since 15+ years

/hannes

On 4/25/17 12:26, Erik Auerswald wrote:
> Hi Xiaohu,
> 
> please see my response inline (content not relevant to this
> response removed).
> 
> On Tue, Apr 25, 2017 at 08:46:06AM +0000, Xuxiaohu wrote:
>>> -----邮件原件-----
>>> 发件人: Erik Auerswald [mailto:auerswald@fg-networking.de]
>>> This idea can be realized using existing implementations, with additional
>>> possible optimizations via IS-IS extensions. In fact I built a lab today to play with
>>> the idea, using a couple of switches, one of which was used as controller, and
>>> the others as fabric switches.
>>
>> It would be great if you could share more information about your experiment:)
> 
> Nothing big, I just took four Extreme Networks X460[-G2] switches from
> the company lab, connected three switches in a row to build the "fabric"
> (you could think of the middle one as "spine" and the two at the ends
> as "leafs"), and then connected the fourth switch to all three "fabric"
> switches to act as "controller". I then configured IS-IS on the switches,
> configured a high metric on the links to/from the "controller" switch,
> and used the "meshBlocked" attribute from RFC 2973 to restrict flooding
> inside the "fabric." To do this I configured "meshBlocked" on all links
> between "fabric" switches.
> 
> Show outputs for transmitted LSPs showed flooding reduction (e.g. when
> adding a new loopback interface on a "leaf" switch), with full IP
> connectivity over the fabric. The "management" links to the "controller"
> were not used for "leaf" to "leaf" traffic due to the higher metric.
> 
>>> RFC 2973, IS-IS Mesh Groups, can be used to prevent flooding on the data path
>>> links.
>>
>> Could you explain more about how to apply the ISIS mesh group in the CLOS topology?
> 
> Please see above. RFC 2973 describes a method to configure individual links
> to inhibit flooding of LSPs using the "meshBlocked" attribute.
> 
> Thanks,
> Erik
>