Re: [Idr] Is the SR Policy SAFI described in draft-ietf-idr-segment-routing-te-policy-07 under the MP-NLRI (code =14) or under the Tunnel Path attribute (code = 23)?

stefano previdi <stefano@previdi.net> Wed, 23 October 2019 09:05 UTC

Return-Path: <stefano@previdi.net>
X-Original-To: idr@ietfa.amsl.com
Delivered-To: idr@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 7EEC91200B4 for <idr@ietfa.amsl.com>; Wed, 23 Oct 2019 02:05:18 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.897
X-Spam-Level:
X-Spam-Status: No, score=-1.897 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_NONE=0.001, URIBL_BLOCKED=0.001] autolearn=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=previdi-net.20150623.gappssmtp.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 iN7k9PnddSDj for <idr@ietfa.amsl.com>; Wed, 23 Oct 2019 02:05:16 -0700 (PDT)
Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) (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 24E9912007A for <idr@ietf.org>; Wed, 23 Oct 2019 02:05:16 -0700 (PDT)
Received: by mail-wr1-x436.google.com with SMTP id r1so11372456wrs.9 for <idr@ietf.org>; Wed, 23 Oct 2019 02:05:16 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=previdi-net.20150623.gappssmtp.com; s=20150623; h=subject:mime-version:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=7er7s0JfOVGAOHE6BAYvCyDiRRTe442vFyU0/TR/kOo=; b=f4DHjcCk4BxbfLQsgYxCNYiBPHmSfLSM/zhM7WMS609O55L1UxUNOnvl7Eyae5ZzJA MnGjTneBo4hj9Yrb/3KQjp/S4HhroACpbDHHzdVb2UKexLfQs5X641yDiREpWbkhQJgY V9ZDlgvyw97ZM/SkTCwR9vQTCQ83PE+KjHehiPTsosxvvQSxUvmYh08K2dZ20DlJ33BV XkPqTNXj/mz/JB7PSaAxqkfr768isDNShhxv1Rc/drTSmqescwvYT3b6+olkXzSALUGX fMTWUnZPY3Jq5cKs8G+jjcBBxOCsAK/re1Q/7gtZ4awCkDtu1OZcQkUfqi3K5VTNaSIG mfQg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:mime-version:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=7er7s0JfOVGAOHE6BAYvCyDiRRTe442vFyU0/TR/kOo=; b=Zca2wF6Oez8mJvFIvALLx7YB3y3p4GalyPb+ftsWFEojuOTbrL58cAF1XwTzcc9mtU ym01dN/H2UxUGnQIRs/KPpNzczIT0cYAnybYQsTs7nsVmIuZw0bJGLwWEURAQOhszSFX Y8sCZFbTw83Q4UxSWgP6urHcvTRC2i9eSTfpmIIUUd0qyIlN54c6BK1VkJZRCRFyQTs9 HPfj0F8X0NCezHWlhRiyBRHlLTPQesm2+YmPP1knZajVDflGFhgfI1kIeJDgrMqmpcBu DFlPQBP3U/cNNcm3s5sNkHV6faZH1W/PlhZNWmDwFA6DIsTufJXMPKOqhp4bNWzqj0gO uEZQ==
X-Gm-Message-State: APjAAAUi0FNMyGiHcrxrEr8E2Eo0q3g3Ab0PXnsnBXOSfF+COh7rbsTs VMlMN/CRhyln9saAzBqe6QO9GVEbh1Q=
X-Google-Smtp-Source: APXvYqxdGJBsqy+3N3dOXuLaUrvqz595hEdW8aufX66uVnQrBVADuY/2CkIFB8ZDjDcg3Bq8s4fFwQ==
X-Received: by 2002:adf:d84c:: with SMTP id k12mr7827015wrl.235.1571821514545; Wed, 23 Oct 2019 02:05:14 -0700 (PDT)
Received: from [192.168.1.5] (net-5-95-15-112.cust.vodafonedsl.it. [5.95.15.112]) by smtp.gmail.com with ESMTPSA id i3sm16904852wrw.69.2019.10.23.02.05.13 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 23 Oct 2019 02:05:13 -0700 (PDT)
Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\))
Content-Type: text/plain; charset=us-ascii
From: stefano previdi <stefano@previdi.net>
In-Reply-To: <BN8PR13MB2628C035A31A9D40F4E07F1485680@BN8PR13MB2628.namprd13.prod.outlook.com>
Date: Wed, 23 Oct 2019 11:05:17 +0200
Cc: "idr@ietf.org" <idr@ietf.org>, "draft-ietf-idr-segment-routing-te-policy@ietf.org" <draft-ietf-idr-segment-routing-te-policy@ietf.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <2F4F86FE-E7AA-4496-BE65-1F0124367399@previdi.net>
References: <BN8PR13MB2628C035A31A9D40F4E07F1485680@BN8PR13MB2628.namprd13.prod.outlook.com>
To: Linda Dunbar <linda.dunbar@futurewei.com>
X-Mailer: Apple Mail (2.2104)
Archived-At: <https://mailarchive.ietf.org/arch/msg/idr/76V58-6Nty9zOpRWNINbfAQLF_A>
Subject: Re: [Idr] Is the SR Policy SAFI described in draft-ietf-idr-segment-routing-te-policy-07 under the MP-NLRI (code =14) or under the Tunnel Path attribute (code = 23)?
X-BeenThere: idr@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Inter-Domain Routing <idr.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/idr>, <mailto:idr-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/idr/>
List-Post: <mailto:idr@ietf.org>
List-Help: <mailto:idr-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/idr>, <mailto:idr-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 23 Oct 2019 09:05:18 -0000

> On Oct 23, 2019, at 1:23 AM, Linda Dunbar <linda.dunbar@futurewei.com> wrote:
> 
> IDR experts and the Authors of draft-ietf-idr-segment-routing-te-policy-07:
>  
> The section 2.1 of draft-ietf-idr-segment-routing-te-policy-07 describes a new SR Policy SAFI under NLRI of BGP UPDATE to advertise SR policies.
>  
> Does it mean that SR Policy SAFI is under the MP-NLRI Path Attribute (Code = 14)?


yes, the nlri with the new safi identifies the policy:
   +------------------+
   |  NLRI Length     | 1 octet
   +------------------+
   |  Distinguisher   | 4 octets
   +------------------+
   |  Policy Color    | 4 octets
   +------------------+
   |  Endpoint        | 4 or 16 octets 
   +------------------+


> The Section 2.2 indicates that SR Policy is encoded in the Tunnel Encapsulation Path Attribute defined in the draft-ietf-idr-tunnel-encaps-12.
>  
> Does it mean the SR policy is also under the Tunnel Path Attribute with Code =23?


the content (i.e., the details) of the sr policy is encoded in the tunnel path attribute.


> Can you please explain is it MP-NLRI Path Attribute or Tunnel Encap Path Attribute that SR policy are encoded?


there are separate items: policy identifier and policy content.

the policy identifier (distinguisher, color, endpoint) goes into the nlri and the policy content (e.g., the segment list) go into the tunnel path attribute.

s.


>  
> Thank you very much. 
>  
> Linda Dunbar