Re: [bess] WGLC, IPR and implementation poll for draft-ietf-bess-mvpn-fast-failover
"Jeffrey (Zhaohui) Zhang" <zzhang@juniper.net> Wed, 13 March 2019 14:32 UTC
Return-Path: <zzhang@juniper.net>
X-Original-To: bess@ietfa.amsl.com
Delivered-To: bess@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 89939130F0D; Wed, 13 Mar 2019 07:32:56 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 0.049
X-Spam-Level:
X-Spam-Status: No, score=0.049 tagged_above=-999 required=5 tests=[DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, KHOP_DYNAMIC=0.85, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=juniper.net
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 dQXJRECim20f; Wed, 13 Mar 2019 07:32:52 -0700 (PDT)
Received: from mx0b-00273201.pphosted.com (mx0b-00273201.pphosted.com [67.231.152.164]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 4164312D7EA; Wed, 13 Mar 2019 07:32:52 -0700 (PDT)
Received: from pps.filterd (m0108160.ppops.net [127.0.0.1]) by mx0b-00273201.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x2DENqik004679; Wed, 13 Mar 2019 07:32:50 -0700
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=juniper.net; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-transfer-encoding : mime-version; s=PPS1017; bh=fxW4O11f4ix8Z00PBL/U/nJ7sP67Xbs9FRm9+jCPOOU=; b=jeNY1/4rJtvnGJMCS6FTD7gj0e0Rf8geQu+SNMMGsRnmKB10UGrgafdDjP3Q4q+i3NcI nWxD7ClgFkBfnKS50ac8rS6uWVNG9HEHKE1/92skV8pK9gUXZLx9lo0FS6BGjwLEZ9Sn PoyDkO5e060GuinLFYEbK6M4YtE7z6FgVGi+AmD3mz1sDuW0RwaNlSanqcincqBLn7fB 2W5fxcJGmgI9L3BFr/9zHZqmBkpTYq5lw/saGTR6/RjnbmePdtII0e2ky69xSgasFwh7 +RgSxAY94crQ9QAdavkVnujXG0l/BonXgxALzdUXbbP8ApgpRPR9gvZZliWrKYE4r8x4 hA==
Received: from nam01-by2-obe.outbound.protection.outlook.com (mail-by2nam01lp2057.outbound.protection.outlook.com [104.47.34.57]) by mx0b-00273201.pphosted.com with ESMTP id 2r6vq5gna2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Wed, 13 Mar 2019 07:32:49 -0700
Received: from SN2PR05MB2463.namprd05.prod.outlook.com (10.166.213.8) by SN2PR05MB2637.namprd05.prod.outlook.com (10.167.14.137) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1709.8; Wed, 13 Mar 2019 14:32:46 +0000
Received: from SN2PR05MB2463.namprd05.prod.outlook.com ([fe80::c84a:45e7:bc68:d17e]) by SN2PR05MB2463.namprd05.prod.outlook.com ([fe80::c84a:45e7:bc68:d17e%6]) with mapi id 15.20.1709.011; Wed, 13 Mar 2019 14:32:46 +0000
From: "Jeffrey (Zhaohui) Zhang" <zzhang@juniper.net>
To: "Mankamana Mishra (mankamis)" <mankamis@cisco.com>
CC: Greg Mirsky <gregimirsky@gmail.com>, "bess-chairs@ietf.org" <bess-chairs@ietf.org>, "EXT - thomas.morin@orange.com" <thomas.morin@orange.com>, Robert Kebler <rkebler@juniper.net>, "bess@ietf.org" <bess@ietf.org>, "EXT-zhang.zheng@zte.com.cn" <zhang.zheng@zte.com.cn>
Thread-Topic: [bess] WGLC,IPR and implementation poll for draft-ietf-bess-mvpn-fast-failover
Thread-Index: AQHU2O7Oo3AajmBtmU+sLBAgGOdNXqYJoUoQ
Date: Wed, 13 Mar 2019 14:32:45 +0000
Message-ID: <SN2PR05MB2463ACF57D2DFDD50F658C7ED44A0@SN2PR05MB2463.namprd05.prod.outlook.com>
References: <CA+RyBmX6RgJ95ptcexEzH8R0ns8xxUhMgL2aAK8xgewcw0-z3w@mail.gmail.com, > <CA+RyBmWeDKVDer+CUJdhnC2Rr3j+SgBNEbiSAmP-TUreD_zW5w@mail.gmail.com> <201902141109309520261@zte.com.cn> <121EFC1D-C7CD-455A-B5A8-B80FA579255B@cisco.com>
In-Reply-To: <121EFC1D-C7CD-455A-B5A8-B80FA579255B@cisco.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
dlp-product: dlpe-windows
dlp-version: 11.1.100.23
dlp-reaction: no-action
x-originating-ip: [66.129.241.12]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: cf21674f-3e68-42c9-0437-08d6a7c0c2b3
x-ms-office365-filtering-ht: Tenant
x-microsoft-antispam: BCL:0; PCL:0; RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600127)(711020)(4605104)(4618075)(2017052603328)(7153060)(7193020); SRVR:SN2PR05MB2637;
x-ms-traffictypediagnostic: SN2PR05MB2637:
x-ms-exchange-purlcount: 1
x-ld-processed: bea78b3c-4cdb-4130-854a-1d193232e5f4,ExtAddr
x-microsoft-antispam-prvs: <SN2PR05MB263743238324930732B5F539D44A0@SN2PR05MB2637.namprd05.prod.outlook.com>
x-forefront-prvs: 09752BC779
x-forefront-antispam-report: SFV:NSPM; SFS:(10019020)(39860400002)(396003)(136003)(346002)(376002)(366004)(13464003)(51444003)(43544003)(37854004)(189003)(199004)(316002)(66066001)(186003)(14454004)(229853002)(486006)(11346002)(476003)(54906003)(478600001)(446003)(71200400001)(71190400001)(256004)(14444005)(52536013)(5024004)(97736004)(102836004)(25786009)(93886005)(5660300002)(86362001)(4326008)(19627235002)(30864003)(966005)(26005)(53936002)(305945005)(74316002)(33656002)(2906002)(106356001)(6306002)(99286004)(6246003)(7696005)(76176011)(53546011)(6506007)(53946003)(9686003)(81166006)(81156014)(8676002)(8936002)(6436002)(105586002)(3846002)(6116002)(68736007)(7736002)(6916009)(55016002)(142933001)(559001)(579004); DIR:OUT; SFP:1102; SCL:1; SRVR:SN2PR05MB2637; H:SN2PR05MB2463.namprd05.prod.outlook.com; FPR:; SPF:None; LANG:en; PTR:InfoNoRecords; MX:1; A:1;
received-spf: None (protection.outlook.com: juniper.net does not designate permitted sender hosts)
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam-message-info: 06NgIcCWWNYgdsJRjSbhI3wnU0R2rxvV8RLdoYy3TrD6fiWaEiS0Dq1wZH4a0LoIYfZ2adYP361aPObbvPlgSXH9KDFmda2T/EJXGa4xBP0bdm5nmIuSAIbZwII0bu1iPQBYcQbcZaIjRMQuq0Zcx7yLlxsadYuaBKvmybrKNpm09juQ4Bdsj2GSyoiKNM4dKBJDWdq//KY8Gn0NnQJSOKorX1/cvtzi+CVOSuYs6z6bIJIowY4OMQ+QG61YpcjnUABhYuBoJoGfHCYMfxiVrXYWZtd1YZQte3sLAjPxGj2NmXgnfAt1GWWEY5WmKdMByM4qi6TRqrQl9ANFbBiWYpyhMBe1nVp1almNKbhKNJMmSy+gmdGYwq01DVe7PUPjGD4kvPtgLG7gis7BE2QH0ck9ZtDWhY3yiL93fn9jbPw=
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
MIME-Version: 1.0
X-OriginatorOrg: juniper.net
X-MS-Exchange-CrossTenant-Network-Message-Id: cf21674f-3e68-42c9-0437-08d6a7c0c2b3
X-MS-Exchange-CrossTenant-originalarrivaltime: 13 Mar 2019 14:32:46.0184 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: bea78b3c-4cdb-4130-854a-1d193232e5f4
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN2PR05MB2637
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-03-13_09:, , signatures=0
X-Proofpoint-Spam-Details: rule=outbound_spam_notspam policy=outbound_spam score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903130104
Archived-At: <https://mailarchive.ietf.org/arch/msg/bess/MQrGDX_NK3dREv8NsMuVNSwANfM>
Subject: Re: [bess] WGLC, IPR and implementation poll for draft-ietf-bess-mvpn-fast-failover
X-BeenThere: bess@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: BGP-Enabled ServiceS working group discussion list <bess.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/bess>, <mailto:bess-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/bess/>
List-Post: <mailto:bess@ietf.org>
List-Help: <mailto:bess-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/bess>, <mailto:bess-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 13 Mar 2019 14:33:04 -0000
Sorry for the delay. Will take care of it this week. Thanks. Jeffrey > -----Original Message----- > From: Mankamana Mishra (mankamis) <mankamis@cisco.com> > Sent: Tuesday, March 12, 2019 12:15 PM > To: Jeffrey (Zhaohui) Zhang <zzhang@juniper.net> > Cc: Greg Mirsky <gregimirsky@gmail.com>; bess-chairs@ietf.org; EXT - > thomas.morin@orange.com <thomas.morin@orange.com>; Robert Kebler > <rkebler@juniper.net>; bess@ietf.org; EXT-zhang.zheng@zte.com.cn > <zhang.zheng@zte.com.cn> > Subject: Re: [bess] WGLC,IPR and implementation poll for draft-ietf-bess- > mvpn-fast-failover > > Hi Jeffery, > wondering if you got chance to updated text & if you are fine with it. > > Mankamana > > > On Feb 13, 2019, at 7:09 PM, zhang.zheng@zte.com.cn wrote: > > > > Hi Greg, > > > > Thank you very much for your clarification! > > I made a mistake that I thought the BFD session is the base solution for UMH > failover. > > Now I get it. Thank you! > > BTW: In section 3.1.2, "draft-ietf-rtgwg-bgp-pic-08" may be mentioned as > another example like MPLS FRR. > > > > Thanks, > > Sandy > > ------------------原始邮件------------------ > > 发件人:GregMirsky <gregimirsky@gmail.com> > > 收件人:张征00007940; > > 抄送人:zzhang@juniper.net <zzhang@juniper.net>;bess-chairs@ietf.org > <bess-chairs@ietf.org>;Thomas Morin <thomas.morin@orange.com>;Robert > Kebler <rkebler@juniper.net>;BESS <bess@ietf.org>; > > 日 期 :2019年02月14日 10:38 > > 主 题 :Re: [bess] WGLC,IPR and implementation poll for draft-ietf-bess- > mvpn-fast-failover > > Hi Sandy, > > thank you for your kind consideration of the proposed updates. I've logged > my answers under GIM3>> tag. > > > > Regards, > > Greg > > > > On Mon, Feb 11, 2019 at 11:44 PM <zhang.zheng@zte.com.cn> wrote: > > Hi Greg, > > Thank you for your good modification and clarification! > > About two sections I still have some comments, I copy the contents here > because the mail is too long: > > 1, > > 3. I am confused with section 3.1.1/3.1.2/3.1.3. IMO only the X-PMSI tunnel's > state influence the BFD session, there is no need for other decision. > > GIM2>> The Upstream PE as MultipointHead of the p2mp BFD session may > use a combination of conditions (the combination being determined by policy) > to control the state of the BFD session, e.g., set it to AdminDown. I think that > the use of policy to control the conditions that affect the P-tunnel reception > state is the advantage of the proposed solution. What do you think? > > 4. For section 3.1.5, IMO the counter method has no relationship with the > BFD function defined in this document. If the counter method will be used as a > supplement for BFD session? > > GIM2>> As above, this is one of the conditions, controlled by the policy, that > may be considered to influence the state of the BFD session. > > Sandy2> Since BFD packet is forwarding through by x-PMSI tunnel, egress PE > can get the tunnel states by BFD detection timer expiration. So administrator > may choose different policies to control the session state, but the bfd packets > detection should be the base. IMO section 3.1.1~4 are optional. > > GIM3>> I re-read the 3.1 and I think now better understand the original idea. > All methods listed in sub-sections, including the one that describes use of > p2mp BFD, are alternatives, options to detect a failure in the tunnel. Would > the following update be helpful: > > OLD TEXT: > > The procedure proposed here also allows that all downstream PEs don't > > apply the same rules to define what the status of a P-tunnel is > > (please see Section 6), and some of them will produce a result that > > may be different for different downstream PEs. > > NEW TEXT: > > The optional procedures proposed in this section also allow that all > downstream PEs don't > > apply the same rules to define what the status of a P-tunnel is > > (please see Section 6), and some of them will produce a result that > > may be different for different downstream PEs. > > > > For section 3.1.5 counter information, how do the configurable timer work > with the bfd detection timer? What should egress PE do with the expiration of > the two timers when they are both used? > > GIM3>> MPLS FRR is mentioned in the draft as an example of the "fast > restoration mechanism". Likely, FRR will be enabled by single-hop p2p BFD per > protected link. If that's the case, for the scenario described in this sub-section, > p2mp BFD is unnecessary. > > > > 2. > > For section 3.1.7.1, the last sentence. > > GIM2>> I think that Jeffrey asked why the new BFD Discriminator must be > sent and the new p2mp BFD session must be initiated. Your question, as I > interpret it, is to how operationally an implementation can minimize the > disruption when the new BFD session advertised to replace one that already > exists. Firstly, would we agree that sending the new BGP-BFD Discriminator > and starting the new p2mp BFD session when the RPF interface changes is the > right action? If we agree, then I can add a sentence or two to describe optional > procedure for the upstream PE to minimize the disruption when the egress PE > switches to the new p2mp BFD session. > > Sandy2>If the "old" BFD discriminator can be reused in the new > advertisement when the switchover is happened on a same upstream PE? If > the "old" discriminator can be reused, it seems like it isn't necessary to build a > new BFD session. But if a new BFD discriminator MUST be generated, then the > new add sentence looks good to me. > > GIM3>> Would the following update to the last paragraph address your > concern: > > OLD TEXT: > > If the route to the > > src/RP changes such that the RPF interface is changed to be a new PE- > > CE interface, then the upstream PE will update the S-PMSI A-D route > > with included BGP-BFD Attribute so that value of the BFD > > Discriminator is associated with the new RPF link. > > NEW TEXT: > > If the route to the > > src/RP changes such that the RPF interface is changed to be a new PE- > > CE interface, then the upstream PE will update the S-PMSI A-D route > > with included BGP-BFD Attribute so that the previously advertised value of > the BFD > > Discriminator is associated with the new RPF link. > > > > Thanks, > > Sandy > > ------------------原始邮件------------------ > > 发件人:GregMirsky <gregimirsky@gmail.com> > > 收件人:张征00007940; > > 抄送人:zzhang@juniper.net <zzhang@juniper.net>;bess-chairs@ietf.org > <bess-chairs@ietf.org>;Thomas Morin <thomas.morin@orange.com>;Robert > Kebler <rkebler@juniper.net>;BESS <bess@ietf.org>; > > 日 期 :2019年02月07日 08:16 > > 主 题 :Re: [bess] WGLC,IPR and implementation poll for draft-ietf-bess- > mvpn-fast-failover > > Hi Sandy,much appreciate your comments. Please find my answers below > tagged GIM2>>. > > Attached, please find the updated working version and the diff to the last > published version. > > Kind regards, > > Greg > > On Thu, Jan 31, 2019 at 7:40 PM <zhang.zheng@zte.com.cn> wrote: > > Hi Greg, Jeffrey, co-authors, > > About the questions provided by Jeffrey, I have some concerns, please see > below with Sandy>. > > And I have some other questions: > > 1. According to "draft-ietf-bfd-multipoint-19" and the function defined in this > draft, IMO the BFD session should be demultiplexed by the combination of > upstream peer address, the discriminator and the X-PMSI which is used for > flow forwarding. IMO these content should be written in the draft clearly. > > GIM2>> Agreed and to clarify I propose the following update to the > Downstream PE Procedures: > > OLD TEXT: > > On receiving the BGP-BFD Attribute in the x-PMSI A-D Route, the > > Downstream PE: > > o MUST associate the received BFD discriminator value with the > > P-tunnel originating from the Root PE; > > o MUST create p2mp BFD session and set bfd.SessionType = > > MultipointTail as described in [I-D.ietf-bfd-multipoint]; > > o MUST use the source IP address of a BFD control packet, the value > > of BFD Discriminator from the BGP-BFD Attribute to properly > > demultiplex BFD sessions; > > NEW TEXT: > > Upon receiving the BGP-BFD Attribute in the x-PMSI A-D Route, the > > Downstream PE: > > o MUST associate the received BFD discriminator value with the > > P-tunnel originating from the Root PE and the IP address of the > > Upstream PE; > > o MUST create p2mp BFD session and set bfd.SessionType = > > MultipointTail as described in [I-D.ietf-bfd-multipoint]; > > o MUST use the source IP address of the BFD control packet, the > > value of the BFD Discriminator field, and the x-PMSI tunnel > > identifier the BFD control packet was received to properly > > demultiplex BFD sessions. > > 2. The P2MP BFD packet should be delivered in the X-PMSI tunnel. The BFD > multicast packet MUST be encapsulated in associated tunnel. It seems like > there is no specifiction for it. > > GIM2>> Agree and to clarify I propose the following text to be added to the > Upstream PE Procedures section: > > NEW TEXT: > > o MUST periodically transmit BFD control packets over the x-PMSI > > tunnel. > > 3. I am confused with section 3.1.1/3.1.2/3.1.3. IMO only the X-PMSI tunnel's > state influence the BFD session, there is no need for other decision. > > GIM2>> The Upstream PE as MultipointHead of the p2mp BFD session may > use a combination of conditions (the combination being determined by policy) > to control the state of the BFD session, e.g., set it to AdminDown. I think that > the use of policy to control the conditions that affect the P-tunnel reception > state is the advantage of the proposed solution. What do you think? > > 4. For section 3.1.5, IMO the counter method has no relationship with the > BFD function defined in this document. If the counter method will be used as a > supplement for BFD session? > > GIM2>> As above, this is one of the conditions, controlled by the policy, that > may be considered to influence the state of the BFD session. > > Thanks, > > Sandy > > 原始邮件 > > 发件人:GregMirsky <gregimirsky@gmail.com> > > 收件人:zzhang@juniper.net <zzhang@juniper.net>; > > 抄送人:bess-chairs@ietf.org <bess-chairs@ietf.org>;Thomas Morin > <thomas.morin@orange.com>;Robert Kebler <rkebler@juniper.net>;BESS > <bess@ietf.org>; > > 日 期 :2018年12月06日 02:38 > > 主 题 :Re: [bess] WGLC,IPR and implementation poll for draft-ietf-bess- > mvpn-fast-failover > > _______________________________________________ > > BESS mailing list > > BESS@ietf.org > > https://urldefense.proofpoint.com/v2/url?u=https- > 3A__www.ietf.org_mailman_listinfo_bess&d=DwIGaQ&c=HAkYuh63rsuhr6Scb > fh0UjBXeMK- > ndb3voDTXcWzoCI&r=f7wsLGcfzAWDNS6XNTBZwj_OLAOsZZqdrR2IDAzeZqE& > m=RMOKFku4FfBJcJIXut6wZWRxOy_iB2nCqiVl6QShD0s&s=m71Y9twizeuNa6A > QckEPQk9PX2R5h7NBU56QIUR5Dz8&e= > > Hi Jeffrey,thank you for the review, detailed questions and helpful comments. > Please find my notes, answers in-line tagged GIM>>. > > Regards, > > Greg > > On Fri, Nov 30, 2018 at 5:14 PM Jeffrey (Zhaohui) Zhang > <zzhang@juniper.net> wrote: > > Hi, > > I have the following questions/comments: > > The procedure described here is an OPTIONAL procedure that consists > > of having a downstream PE take into account the status of P-tunnels > > rooted at each possible upstream PEs, for including or not including > > each given PE in the list of candidate UMHs for a given (C-S,C-G) > > state. The result is that, if a P-tunnel is "down" (see > > Section 3.1), the PE that is the root of the P-tunnel will not be > > considered for UMH selection, which will result in the downstream PE > > to failover to the upstream PE which is next in the list of > > candidates. > > Is it possible that a p2mp tunnel is considered up by some leaves but down > by some other leaves, leaving to them choosing different UMH? In that case, > procedures described in Section 9.1.1 ("Discarding Packets from Wrong PE") of > RFC 6513 must be used. I see that this is actually pointed out later in section 6 > – good to have a pointer to it right here. > > GIM>> Would the following new text that follows the quoted text address > your concern: > > NEW TEXT: > > If rules to determine the state of the P-tunnel are not > > consistent across all PEs, then some may arrive at a different > > conclusion regarding the state of the tunnel, In such a scenario, > > procedures described in Section 9.1.1 of [RFC 6513] MUST be used. > > Sandy> I think Jeffrey means that a egress PE may choose a new UMH after > the the "old" UMH fails. Then the egress PE may also receive (C-S, C-G) flows > from old UMH p-tunnel, these flows MUST be discarded according to section > 9.1.1 of RFC6513. > > GIM2>> I think that the proposed text may address the comment. I'm,as > always, open to suggestions on how to modify, refine the proposed new text. > > Additionally, the text in section 3 seems to be more biased on Single > Forwarder Election choosing the UMH with the highest IP address. Section 5 of > RFC6513 also describes two other options, hashing or based on “installed UMH > route” (aka unicast-based). It is not clear how the text in this document applies > to hashing based selection, and I don’t see how the text applies to unicast- > based selection. Some rewording/clarification are needed here. > > GIM>> How would the use of an alternative UMH selection algorithm > change documented use of p2mp BFD? Do you think that if the Upstream PE > selected using, for example, hashing then defined use of BGP-BFD and p2mp > BFD itself no longer applicable? > > Sandy> Diffrent UMH selection methods don't influent p2mp BFD > documented in this draft. IMO both of section 3 and section 5 need to be > mentioned here in order to avoid confusion. > > GIM2>> Very helpful clarification, thank you. Please consider the following > update to section 4: > > OLD TEXT: > > The procedures > > require all the PEs of that MVPN to follow the single forwarder PE > > selection, as specified in [RFC6513]. > > NEW TEXT: > > The procedures > > require all the PEs of that MVPN to follow the single forwarder PE > > selection, as specified in [RFC6513], whether the PE selected based > > on its IP address, hashing algorithm described in section 5.1.3 > > [RFC6513], or Installed UMH Route. > > For P-tunnels of type P2MP MPLS-TE, the status of the P-tunnel is > > considered up if one or more of the P2MP RSVP-TE LSPs, identified by > > the P-tunnel Attribute, are in Up state. > > Why is “one or more of …” used in the above text? > > GIM>> Would s/one or more of/at least one of/ address your concern? > > Sandy> I am not sure there are the situations that two or more LSPs are > used to deliver a same (C-S, C-G). IMO only the LSP used by forwarding need > to be mointor in egress PE. > > GIM>> I need to defer this to Thomas and Rob. If you agree with Sandy, > should we just remove the sentence? > > There are several occurrences of ((S, G)). I assume they should be changed > to (C-S, C-G). > > GIM>> Indeed, globally replaced s/((S,G))/(C-S,C-G)/ > > A PE can be removed from the UMH candidate list for a given ((S, G)) > > if the P-tunnel for this (S, G) (I or S , depending) is leaf > > triggered (PIM, mLDP) > > Perhaps either remove the (I or S , depending)or move it to before the “for”. > > GIM>> Moved before the "for". > > This document defines the format and ways of usingr a new BGP > > attribute called the "BGP- BFD attribute". > > s/usingr/using/ > > GIM>> Yes, great catch. > > o MUST use [Ed.note] address as destination IP address when > > transmitting BFD control packets; > > [Ed.note]? > > GIM>> Replaced [Ed...note] to make it as follows: > > o MUST use address in 127.0.0.0/8 range for IPv4 or in > > 0:0:0:0:0:FFFF:7F00:0/104 range for IPv6 as destination IP address > > when transmitting BFD control packets; > > If tracking of the P-tunnel by using a p2mp BFD session is to be > > enabled after the P-tunnel has been already signaled, the the > > procedure described above MUST be followed. > > What if the tracking is to be enabled before the P-tunnel has been signaled? > The text implies different behavior? > > GIM>> Not really, I guess. I think that the second sentence is important: > > Note that x-PMSI A-D Route MUST be re-sent with exactly the same > attributes as before and > > the BGP-BFD Attribute included. > > s/the the/then the/ > > GIM>> Done. > > … The dedicated p2mp BFD session MAY monitor the state of > > the Standby Upstream PE. > > What does the above text mean? Do you mean “A different p2mp BFD > session …”? > > GIM>> Yes, thank you for the suggested re-wording. Applied s/The > dedicated/A different/ > > When such a procedure is used, in the context where fast restoration > > mechanisms are used for the P-tunnels, leaf PEs should be configured > > to wait before updating the UMH, to let the P-tunnel restoration > > mechanism happen. A configurable timer MUST be provided for this > > purpose, and it is recommended to provide a reasonable default value > > for this timer. > > What does “such a procedure” refers to? > > GIM>> Would s/When such a procedure is used/In such a scenario/ > > s/recommended/RECOMMENDED/? > > GIM>> Great catch, thank you. Done. > > 3.1.7. Per PE-CE link BFD Discriminator > > The following approach is defined for the fast failover in response > > to the detection of PE-CE link failures, in which UMH selection for a > > given C-multicast route takes into account the state of the BFD > > session associated with the state of the upstream PE-CE link. > > 3.1.7.1. Upstream PE Procedures > > For each protected PE-CE link, the upstream PE initiates a multipoint > > BFD session [I-D.ietf-bfd-multipoint] as MultipointHead toward > > downstream PEs. A downstream PE monitors the state of the p2mp > > session as MultipointTail and MAY interpret transition of the BFD > > session into Down state as the indication of the associated PE-CE > > link being down. > > Since the BFD packets are sent over the P2MP tunnel not the PE-CE link, my > understanding is that the BFD discriminator is still for the tunnel and not tied > to the PE-CE link; but different from the previous case, the root will stop > sending BFD messages when it detects the PE-CE link failure. As far as the > egress PEs are concerned, they don’t know if it is the tunnel failure or PE-CE > link failure. > > If my understanding is correct, the wording should be changed. > > GIM>> There are other than stopping transmission of BFD control packets > ways to distinguish two conditions for the egress PE. For example, the > MultipointHead MAY set the State to AdminDown and continue sending BFD > control packets. If and when PE-CE link restored to Up, the MultipointHead can > set the state to Up in the BFD control packet. > > Sandy> I agree with Jeffrey. The BFD detection should be mapping to specific > flow/flows associated with X-PMSIs, not the PE-CE link. The PE-CE link should > influence the X-PMSIs and associated (C-S, C-G) flows. The AdminDown > function defined in BFD works normally. > > GIM2>> The described behavior of the egress PE is optional and can be > controlled by the local policy. > > … If the route to the > > src/RP changes such that the RPF interface is changed to be a new PE- > > CE interface, then the upstream PE will update the S-PMSI A-D route > > with included BGP-BFD Attribute so that value of the BFD > > Discriminator is associated with the new RPF link. > > If the RPF interface changes on the upstream PE, why should it update the > route to send a new discriminator? As long as there is a new RPF interface > couldn’t the upstream PE do nothing but start tracking the new RPF interface? > > GIM>> I'll defer this one to Thomas and Rob. > > Sandy> I have the same question with Jeffrey. If RPF interface changes on > the upstream PE, and a new route generated with a new BFD discriminator, a > new P2MP BFD session need to be established and the network stability will be > influenced. We need a function to guarantee the existed BFD session should > not be influenced. > > GIM2>> I think that Jeffrey asked why the new BFD Discriminator must be > sent and the new p2mp BFD session must be initiated. Your question, as I > interpret it, is to how operationally an implementation can minimize the > disruption when the new BFD session advertised to replace one that already > exists. Firstly, would we agree that sending the new BGP-BFD Discriminator > and starting the new p2mp BFD session when the RPF interface changes is the > right action? If we agree, then I can add a sentence or two to describe optional > procedure for the upstream PE to minimize the disruption when the egress PE > switches to the new p2mp BFD session. > > Regardless which way (the currently described way and my imagined way), > some text should be added to discuss how the downstream would not switch to > another upstream PE when the primary PE is just going through a RPF change. > > GIM>> Would appending the following text be acceptable to address your > concern: > > NEW TEXT: > > To avoid unwarranted switchover a downstream PE MUST gracefully handle > the > > updated S-PMSI A-D route and switch to the use of the associated BFD > > Discriminator value. > > 4. Standby C-multicast route > > The procedures described below are limited to the case where the site > > that contains C-S is connected to exactly two PEs. The procedures > > require all the PEs of that MVPN to follow the single forwarder PE > > selection, as specified in [RFC6513]. > > Why would it not work with more than two upstream PEs? > > Why is it limited to single forwarder selection? What about unicast based > selection? > > GIM>> Again, asking for Thomas and Rob to help. > > Sandy> I agree with Jeffrey. There is no limition for advertising same flows > through more than two PEs. Maybe the text should be modify to the UMH and > the next best UMH. > > GIM2>> Thank you for the suggestion. Jeffrey and Sandy, would the > following update address your concerns: > > OLD TEXT: > > The procedures described below are limited to the case where the site > > that contains C-S is connected to exactly two PEs. The procedures > > require all the PEs of that MVPN to follow the single forwarder PE > > selection, as specified in [RFC6513]. > > NEW TEXT: > > The procedures described below are limited to the case where the site > > that contains C-S is connected to two or more PEs though, to simplify > > the description, the case of dual-homing is described. The > > procedures require all the PEs of that MVPN to follow the UMH > > selection, as specified in [RFC6513], whether the PE selected based > > on its IP address, hashing algorithm described in section 5.1.3 > > [RFC6513], or Installed UMH Route. > > This route, that has the semantics of being a 'standby' > > C-multicast route, is further called a "Standby BGP C-multicast > > route", and is constructed as follows: > > o the NLRI is constructed as the original C-multicast route, except > > that the RD is the same as if the C-multicast route was built > > using the standby PE as the UMH (it will carry the RD associated > > to the unicast VPN route advertised by the standby PE for S) > > Since you mention RD, you might as well mention it carries a Route Target > derived from the standby RE’s UMH route’s VRF RT Import EC. > > GIM>> Woud the following be acceptable: > > NEW TEXT: > > o the NLRI is constructed as the original C-multicast route, except > > that the RD is the same as if the C-multicast route was built > > using the standby PE as the UMH (it will carry the RD associated > > to the unicast VPN route advertised by the standby PE for S and a > > Route Target derived from the standby PE's UMH route's VRF RT > > Import EC) > > If at some later point the local PE determines that C-S is no longer > > reachable through the Primary Upstream PE, the Standby Upstream PE > > becomes the Upstream PE, and the local PE re-sends the C-multicast > > route with RT that identifies the Standby Upstream PE, except that > > now the route does not carry the Standby PE BGP Community (which > > results in replacing the old route with a new route, with the only > > difference between these routes being the presence/absence of the > > Standby PE BGP Community). > > Additionally the LOCAL_PREF should also change? > > GIM>> Like normative SHOULD? > > 4.3. Reachability determination > > The standby PE can use the following information to determine that > > C-S can or cannot be reached through the primary PE: > > Shouldn’t this be 4.2.1 instead of 4.3? > > GIM>> Yes, agree. Thank you. > > 5. Hot leaf standby > > The mechanisms defined in sections Section 4 and Section 3 can be > > used together as follows. > > This section is a little confusing to me. It seems that it really should be how > a leaf should behave when hot root standby is used, not that there is a “hot > leaf” mode. A leaf is just a leaf, not a cold/warm/hot/primary/standby leaf. > > GIM>> Would re-naming the section to "Use of Standby C-multicast Route" > better reflect the content of the section? > > Thanks. > > Jeffrey > > From: BESS <bess-bounces@ietf.org> On Behalf Of > stephane.litkowski@orange.com > > Sent: Thursday, November 22, 2018 2:54 AM > > To: bess@ietf.org > > Cc: bess-chairs@ietf.org > > Subject: [bess] WGLC, IPR and implementation poll for draft-ietf-bess-mvpn- > fast-failover > > Hello Working Group, > > This email starts a two-week Working Group Last Call on draft-ietf-bess- > mvpn-fast-failover-04 [1] > > This poll runs until *the 6th of December*. > > We are also polling for knowledge of any undisclosed IPR that applies to this > Document, to ensure that IPR has been disclosed in compliance with IETF IPR > rules (see RFCs 3979, 4879, 3669 and 5378 for more details). > > If you are listed as an Author or a Contributor of this Document please > respond to this email and indicate whether or not you are aware of any > relevant undisclosed IPR. The Document won't progress without answers from > all the Authors and Contributors. > > Currently two IPRs have been disclosed against this Document. > > If you are not listed as an Author or a Contributor, then please explicitly > respond only if you are aware of any IPR that has not yet been disclosed in > conformance with IETF rules. > > We are also polling for any existing implementation as per [2]. > > Thank you, > > Stephane & Matthew > > [1] https://urldefense.proofpoint.com/v2/url?u=https- > 3A__datatracker.ietf.org_doc_draft-2Dietf-2Dbess-2Dmvpn-2Dfast- > 2Dfailover_&d=DwIGaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK- > ndb3voDTXcWzoCI&r=f7wsLGcfzAWDNS6XNTBZwj_OLAOsZZqdrR2IDAzeZqE& > m=RMOKFku4FfBJcJIXut6wZWRxOy_iB2nCqiVl6QShD0s&s=vCfbC9yPtZ9qAFQx > uTmruzhDLGsbxGOeOEVZTkLi0-A&e= > > [2] https://urldefense.proofpoint.com/v2/url?u=https- > 3A__mailarchive.ietf.org_arch_msg_bess_cG3X1tTqb- > 5FvPC4rg56SEdkjqDpw&d=DwIGaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK- > ndb3voDTXcWzoCI&r=f7wsLGcfzAWDNS6XNTBZwj_OLAOsZZqdrR2IDAzeZqE& > m=RMOKFku4FfBJcJIXut6wZWRxOy_iB2nCqiVl6QShD0s&s=D_VQGRJF- > 5egcJD7ddZBtfxn2orUYTGrsrks6RHw2Oo&e= > > > ________________________________________________________________ > _________________________________________________________ > > Ce message et ses pieces jointes peuvent contenir des informations > confidentielles ou privilegiees et ne doivent donc > > pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce > message par erreur, veuillez le signaler > > a l'expediteur et le detruire ainsi que les pieces jointes. Les messages > electroniques etant susceptibles d'alteration, > > Orange decline toute responsabilite si ce message a ete altere, deforme ou > falsifie. Merci. > > This message and its attachments may contain confidential or privileged > information that may be protected by law; > > they should not be distributed, used or copied without authorisation. > > If you have received this email in error, please notify the sender and delete > this message and its attachments. > > As emails may be altered, Orange is not liable for messages that have been > modified, changed or falsified. > > Thank you.
- [bess] WGLC, IPR and implementation poll for draf… stephane.litkowski
- Re: [bess] WGLC, IPR and implementation poll for … Thomas Morin
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC, IPR and implementation poll for … Robert Kebler
- Re: [bess] WGLC, IPR and implementation poll for … Jeffrey (Zhaohui) Zhang
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC, IPR and implementation poll for … stephane.litkowski
- Re: [bess] WGLC,IPR and implementation poll for d… zhang.zheng
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC,IPR and implementation poll for d… zhang.zheng
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC,IPR and implementation poll for d… zhang.zheng
- Re: [bess] WGLC, IPR and implementation poll for … Mankamana Mishra (mankamis)
- Re: [bess] WGLC, IPR and implementation poll for … Jeffrey (Zhaohui) Zhang
- Re: [bess] WGLC, IPR and implementation poll for … Jeffrey (Zhaohui) Zhang
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC, IPR and implementation poll for … Jeffrey (Zhaohui) Zhang
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC, IPR and implementation poll for … Jeffrey (Zhaohui) Zhang
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC, IPR and implementation poll for … Jeffrey (Zhaohui) Zhang
- Re: [bess] WGLC, IPR and implementation poll for … Greg Mirsky
- Re: [bess] WGLC, IPR and implementation poll for … Jeffrey (Zhaohui) Zhang