Re: [Lsr] Concerns with draft-chunduri-lsr-isis-preferred-path-routing

Peter Psenak <ppsenak@cisco.com> Wed, 18 July 2018 15:23 UTC

Return-Path: <ppsenak@cisco.com>
X-Original-To: lsr@ietfa.amsl.com
Delivered-To: lsr@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 447D7130F2B; Wed, 18 Jul 2018 08:23:42 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.51
X-Spam-Level:
X-Spam-Status: No, score=-14.51 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-0.001, T_DKIMWL_WL_HIGH=-0.01, URIBL_BLOCKED=0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cisco.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 E3z_1Inzx1XT; Wed, 18 Jul 2018 08:23:40 -0700 (PDT)
Received: from aer-iport-3.cisco.com (aer-iport-3.cisco.com [173.38.203.53]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 4EFFE131167; Wed, 18 Jul 2018 08:23:39 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=1297; q=dns/txt; s=iport; t=1531927419; x=1533137019; h=message-id:date:from:mime-version:to:cc:subject: references:in-reply-to:content-transfer-encoding; bh=vsIqsfbw/IS9rhFlgF0ldUswy5G6Oie6WpKPkWfCjUc=; b=jWPLoOla2owa/PsptSmGlIkHTx9hotD9zsRM8/fYm/gNoy4bdSAhVSgh 1EhVL3SGcva1BkfoC1Lsw65bdHUHmKnVpnOw6kmh7WQacw9AHLZWdD2PK mGaZLLeFvFQXyRv8NmU3L6ZavGNpHsbrojmGv0VqXUsGzbg0n5vza/8sK s=;
X-IronPort-AV: E=Sophos;i="5.51,370,1526342400"; d="scan'208";a="5197913"
Received: from aer-iport-nat.cisco.com (HELO aer-core-4.cisco.com) ([173.38.203.22]) by aer-iport-3.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Jul 2018 15:23:37 +0000
Received: from [10.86.242.4] (che-vpn-cluster-2-4.cisco.com [10.86.242.4]) by aer-core-4.cisco.com (8.15.2/8.15.2) with ESMTP id w6IFNZUN029454; Wed, 18 Jul 2018 15:23:36 GMT
Message-ID: <5B4F5B76.30002@cisco.com>
Date: Wed, 18 Jul 2018 11:23:34 -0400
From: Peter Psenak <ppsenak@cisco.com>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:24.0) Gecko/20100101 Thunderbird/24.4.0
MIME-Version: 1.0
To: Uma Chunduri <uma.chunduri@huawei.com>, "Ketan Talaulikar (ketant)" <ketant@cisco.com>, "lsr@ietf.org" <lsr@ietf.org>
CC: "spring@ietf.org" <spring@ietf.org>
References: <5a180e3dc86047beb3991ad8b1d6d54d@XCH-ALN-008.cisco.com> <25B4902B1192E84696414485F5726854135F192C@sjceml521-mbx.china.huawei.com> <5B4DF040.6050004@cisco.com> <25B4902B1192E84696414485F5726854135F1997@sjceml521-mbx.china.huawei.com>
In-Reply-To: <25B4902B1192E84696414485F5726854135F1997@sjceml521-mbx.china.huawei.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/lsr/6TzBBkmq4hQkiqyBeuN7MMOtMs0>
Subject: Re: [Lsr] Concerns with draft-chunduri-lsr-isis-preferred-path-routing
X-BeenThere: lsr@ietf.org
X-Mailman-Version: 2.1.27
Precedence: list
List-Id: Link State Routing Working Group <lsr.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/lsr>, <mailto:lsr-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/lsr/>
List-Post: <mailto:lsr@ietf.org>
List-Help: <mailto:lsr-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/lsr>, <mailto:lsr-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 18 Jul 2018 15:23:42 -0000

Hi Uma,

On 17/07/18 09:43 , Uma Chunduri wrote:
> Hi Peter,
>
>
> -----Original Message-----
> From: Peter Psenak [mailto:ppsenak@cisco.com]
> Sent: Tuesday, July 17, 2018 9:34 AM
> To: Uma Chunduri <uma.chunduri@huawei.com>om>; Ketan Talaulikar (ketant) <ketant@cisco.com>om>; lsr@ietf.org
> Cc: spring@ietf.org
> Subject: Re: [Lsr] Concerns with draft-chunduri-lsr-isis-preferred-path-routing
>
>
> 	> flex-algo is NOT a per path state. It's a regular prefix-SID, which is bound to a prefix only.
>
> Not quite. I will come back to this bit later.

please do so, as I don't know what do you mean by "Not quite".

>
> 	>The problem with your proposal is that you flood all paths to all routers in the area and ask every router to evaluate all of them and see which of them may apply. This scale poorly.
>
> Please see Section 6, in 01 version.

the section 6 points to a solution that does not exist as of yet. I can 
only comment once it is available, but the fact that you need an extra 
hooks to address the scalability just confirms the limited scaling 
property of the basic proposal.

thanks,
Peter

>
> --
> Uma C.
>
> _______________________________________________
> Lsr mailing list
> Lsr@ietf.org
> https://www.ietf.org/mailman/listinfo/lsr
> .
>