Re: [spring] SRv6 BGP based Overlay Services (draft-ietf-bess-srv6-services-07)

Shraddha Hegde <shraddha@juniper.net> Tue, 20 July 2021 05:20 UTC

Return-Path: <shraddha@juniper.net>
X-Original-To: spring@ietfa.amsl.com
Delivered-To: spring@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 03A043A1157; Mon, 19 Jul 2021 22:20:49 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.548
X-Spam-Level:
X-Spam-Status: No, score=-2.548 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.452, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=0.001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-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=juniper.net header.b=EHO2x2gN; dkim=pass (1024-bit key) header.d=juniper.net header.b=Bf04hJFj
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 kdOBnvox41s7; Mon, 19 Jul 2021 22:20:43 -0700 (PDT)
Received: from mx0a-00273201.pphosted.com (mx0a-00273201.pphosted.com [208.84.65.16]) (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 3A2E33A1155; Mon, 19 Jul 2021 22:20:43 -0700 (PDT)
Received: from pps.filterd (m0108158.ppops.net [127.0.0.1]) by mx0a-00273201.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 16K591hi031502; Mon, 19 Jul 2021 22:18:36 -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 : mime-version; s=PPS1017; bh=aakGFRTcicNU8aYvfdsnFrSZTTV2LoSJKMWM50bCS94=; b=EHO2x2gNXd5KvhSP2mB6j0tqCrSYBMEnBneAN+R299EG/JIE/qBaKbU9MGyg8Hixcu6X 0HJB1vFXKz8uFMX0uL8Q8FcliuCKuusN7lcaJTDTaM4b3nGwlTv0kWll1H7eHljoxQF5 aJHWqswNWtuALjY9Dmgm+XKBJRtrqNYkm+Q+soEr9a89zZEHGvD0yo7q+RWS4PjRwqLs qXjtSYZzK+//RBesvf49lp9K/mtzne4OPoqA0q1CXLhIpiTg1iD7J72togNT24gbJR3f kv7cXBhWnPN7vVAsukGu7DDBGkhqNw8xpniLqfY/Jbb+ba9elHRbLkmwb7sztJRc4Cae hw==
Received: from nam12-mw2-obe.outbound.protection.outlook.com (mail-mw2nam12lp2047.outbound.protection.outlook.com [104.47.66.47]) by mx0a-00273201.pphosted.com with ESMTP id 39w248a64t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 19 Jul 2021 22:18:35 -0700
ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=OhiTlW4XwOTziRA4fyWVuCV+AMtAHETcduwH+xcil0/m+rJ8kkXLMVARCiLmREL0sou2vXoAT/82fccz+KNS1XFT1qnQ4fwunw+FLebBr6cfWNs3JWsv4SdNrT08ZTzncYt356kCMCnhbdF8T9iVdGUqQYOyniWm2IEaTPwjHlO2mYZuH1WMJTG6vGwCXRx+uukBm0Y1P4YapOQwjOyJ4ZRPb7oHWh9WureW1zDOyjnNaE1eG29xUFHM6iHtbfL8xeSdloTSVTRbmW3Eq1BJpPWIMWBcAz6CjVfRTTznpSFuLvf3tAwjA55KbETbmwpPdh/W/NZWiEVEW/ExEK+iKg==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=aakGFRTcicNU8aYvfdsnFrSZTTV2LoSJKMWM50bCS94=; b=liHzaXic2qAvIPh8WsBXzm4X6UTX2rAJDUSYDQkCTwWsmhTslEMeOzpVK6HB7NHSMyUaEq64V7Jx2/mK9FJi4+vnSeK/iA3jXISVix5NdtQjRD2+dP5t+4cFznHE4L/vZ8AB6F6hGJt5adju8GJPfWSu6IJeeDSrG0zV9eFG1QYHXhb2tl5U7UvKw4GPFoXG+NjoERmk41N+Yq5CfopdXXqEDqjUArNF/1BZBFNPrAtVB3WVhFdN7OWqcF9DhEs7dIJIpEIFGpO6ibYGgAL38H3JGRLOasHhNnKHQrPGwp4aKckLL9GaLDW6PGdiaQymAjobsWOeHptkSXf+nYdtpA==
ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=juniper.net; dmarc=pass action=none header.from=juniper.net; dkim=pass header.d=juniper.net; arc=none
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=juniper.net; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=aakGFRTcicNU8aYvfdsnFrSZTTV2LoSJKMWM50bCS94=; b=Bf04hJFjx1+aBfkDZZFmmwrXvcMZa3EUR4A0GDg1thW9SVY3sQuoSFKINGf4qBTo3ahPU0cQQg82EwkTJs917ClkEYe09Nkd7Zc9AUma8G5VwGi7VUyA0IaAISg4Ry2M2aPc7XB5nj9+fQ+fr5KjQgZvMW7yjouQcKS1vSIi9EE=
Received: from CY4PR05MB3576.namprd05.prod.outlook.com (2603:10b6:910:52::22) by CY4PR0501MB3715.namprd05.prod.outlook.com (2603:10b6:910:90::29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4352.17; Tue, 20 Jul 2021 05:18:33 +0000
Received: from CY4PR05MB3576.namprd05.prod.outlook.com ([fe80::e89d:19b2:fcb6:8288]) by CY4PR05MB3576.namprd05.prod.outlook.com ([fe80::e89d:19b2:fcb6:8288%7]) with mapi id 15.20.4352.022; Tue, 20 Jul 2021 05:18:33 +0000
From: Shraddha Hegde <shraddha@juniper.net>
To: "Aissaoui, Mustapha (Nokia - CA/Ottawa)" <mustapha.aissaoui@nokia.com>, "Rabadan, Jorge (Nokia - US/Mountain View)" <jorge.rabadan@nokia.com>, Rajesh M <mrajesh@juniper.net>, Rajesh M <mrajesh=40juniper.net@dmarc.ietf.org>, "Ketan Talaulikar (ketant)" <ketant@cisco.com>, "gdawra.ietf@gmail.com" <gdawra.ietf@gmail.com>, "Clarence Filsfils (cfilsfil)" <cfilsfil@cisco.com>, "robert@raszuk.net" <robert@raszuk.net>, "bruno.decraene@orange.com" <bruno.decraene@orange.com>
CC: "spring@ietf.org" <spring@ietf.org>, "bgp@ans.net" <bgp@ans.net>, Srihari Sangli <ssangli@juniper.net>, "bess@ietf.org" <bess@ietf.org>
Thread-Topic: SRv6 BGP based Overlay Services (draft-ietf-bess-srv6-services-07)
Thread-Index: Add5ZuxHtH2qrBhRQGK4/wpw+iW7/ADOgmjgAAC4i7gAAK6ykAAfQY4A
Date: Tue, 20 Jul 2021 05:18:33 +0000
Message-ID: <CY4PR05MB3576D4484BD96F6E08604AF4D5E29@CY4PR05MB3576.namprd05.prod.outlook.com>
References: <BN6PR05MB36346DDD4F6824CD65D70491BE129@BN6PR05MB3634.namprd05.prod.outlook.com>, <BN6PR05MB36341943DEC7D8DC5869A9E0BEE19@BN6PR05MB3634.namprd05.prod.outlook.com> <BY3PR08MB70603EB604AF65D3580E3794F7E19@BY3PR08MB7060.namprd08.prod.outlook.com> <DM6PR08MB6027C9A41B6B1DF2BB59687FE4E19@DM6PR08MB6027.namprd08.prod.outlook.com>
In-Reply-To: <DM6PR08MB6027C9A41B6B1DF2BB59687FE4E19@DM6PR08MB6027.namprd08.prod.outlook.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
dlp-product: dlpe-windows
dlp-version: 11.6.100.41
dlp-reaction: no-action
msip_labels: MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_Enabled=true; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_SetDate=2021-07-20T05:18:31Z; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_Method=Standard; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_Name=0633b888-ae0d-4341-a75f-06e04137d755; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_SiteId=bea78b3c-4cdb-4130-854a-1d193232e5f4; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_ContentBits=2
authentication-results: nokia.com; dkim=none (message not signed) header.d=none;nokia.com; dmarc=none action=none header.from=juniper.net;
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: f0733ec7-2b36-4cc7-1b5c-08d94b3dd1cf
x-ms-traffictypediagnostic: CY4PR0501MB3715:
x-ms-exchange-transport-forked: True
x-microsoft-antispam-prvs: <CY4PR0501MB3715B72060FDBCC04CA97CC0D5E29@CY4PR0501MB3715.namprd05.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:10000;
x-ms-exchange-senderadcheck: 1
x-ms-exchange-antispam-relay: 0
x-microsoft-antispam: BCL:0;
x-microsoft-antispam-message-info: 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
x-forefront-antispam-report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:CY4PR05MB3576.namprd05.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(366004)(316002)(2906002)(508600001)(9326002)(33656002)(55016002)(83380400001)(8676002)(7416002)(7696005)(53546011)(5660300002)(110136005)(86362001)(8936002)(6506007)(296002)(4326008)(38100700002)(71200400001)(122000001)(186003)(52536014)(76116006)(66556008)(64756008)(66476007)(9686003)(921005)(66946007)(26005)(66446008)(54906003)(38070700004); DIR:OUT; SFP:1102;
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: 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
Content-Type: multipart/alternative; boundary="_000_CY4PR05MB3576D4484BD96F6E08604AF4D5E29CY4PR05MB3576namp_"
MIME-Version: 1.0
X-OriginatorOrg: juniper.net
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: CY4PR05MB3576.namprd05.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: f0733ec7-2b36-4cc7-1b5c-08d94b3dd1cf
X-MS-Exchange-CrossTenant-originalarrivaltime: 20 Jul 2021 05:18:33.3545 (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-CrossTenant-userprincipalname: ATnV/yaJLJ/8aZCC36e0Mahfu1/k1FvET4ICcSU+Z7M/LXwG2aIyeiZHhqgz6gZSToJzAroZY2L4ZGPZaiTiYg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR0501MB3715
X-Proofpoint-GUID: mBNhRqguMgCb6w496_SY9FAyGXtz4nMR
X-Proofpoint-ORIG-GUID: mBNhRqguMgCb6w496_SY9FAyGXtz4nMR
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391, 18.0.790 definitions=2021-07-20_01:2021-07-19, 2021-07-20 signatures=0
X-Proofpoint-Spam-Details: rule=outbound_spam_notspam policy=outbound_spam score=0 priorityscore=1501 malwarescore=0 adultscore=0 spamscore=0 clxscore=1011 impostorscore=0 suspectscore=0 lowpriorityscore=0 mlxscore=0 mlxlogscore=999 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2107200029
Archived-At: <https://mailarchive.ietf.org/arch/msg/spring/xm7xzLz2VHjXl8DT25iZI_4EwQk>
Subject: Re: [spring] SRv6 BGP based Overlay Services (draft-ietf-bess-srv6-services-07)
X-BeenThere: spring@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Source Packet Routing in NetworkinG \(SPRING\)" <spring.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/spring>, <mailto:spring-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/spring/>
List-Post: <mailto:spring@ietf.org>
List-Help: <mailto:spring-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/spring>, <mailto:spring-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 20 Jul 2021 05:20:49 -0000

Hi Authors,

There is a possibility of a usecase that wants to use flex-algo paths if available and if flex-algo paths
Are not available use best effort paths.


"When providing best-effort connectivity to the egress PE, the ingress
   PE encapsulates the payload in an outer IPv6 header where the
   destination address is the SRv6 Service SID associated with the
   related BGP route update.  Therefore, the ingress PE SHOULD perform
   resolvability check for the SRv6 Service SID before considering the
   received prefix for the BGP best path computation.
"

The current text says for best effort tunnels Srv6 service SID resolution SHOULD be checked and
I am told that (from previous mailing list exchanges) authors intend to update the text to make it applicable for flex-algo connectivity  as well.

It is not possible to support fallback on best effort tunnels if flex-algo SRv6 service SIDs have to be resolved.
It is possible to support fallback to best effort in SRv6 if packets can be tunneled to egress PE  (destination address being PE's best effort END SID and service SID in the SRH)and
then do a service SID lookup on egress, in which case there is no need to resolve the SRv6 service SIDs on the ingress.

It is not clear whether the authors intend to support these kind of tunnelling to egress cases for
Best effort and flex-algo transport. If it not going to be supported, pls add text indicating clearly
Tunnelling is not required to be supported and hence Fallback to best effort  is also not supported.

If that is not the intention, Its reasonable to update the text to indicate SRv6 service SIDs need not be resolved
If the ingress is tunneling the packet.

Rgds
Shraddha


Juniper Business Use Only
From: spring <spring-bounces@ietf.org> On Behalf Of Aissaoui, Mustapha (Nokia - CA/Ottawa)
Sent: Monday, July 19, 2021 7:34 PM
To: Rabadan, Jorge (Nokia - US/Mountain View) <jorge.rabadan@nokia.com>; Rajesh M <mrajesh@juniper.net>; Rajesh M <mrajesh=40juniper.net@dmarc.ietf.org>; Ketan Talaulikar (ketant) <ketant@cisco.com>; gdawra.ietf@gmail.com; Clarence Filsfils (cfilsfil) <cfilsfil@cisco.com>; robert@raszuk.net; bruno.decraene@orange.com
Cc: spring@ietf.org; bgp@ans.net; Srihari Sangli <ssangli@juniper.net>; bess@ietf.org; Shraddha Hegde <shraddha@juniper.net>
Subject: Re: [spring] SRv6 BGP based Overlay Services (draft-ietf-bess-srv6-services-07)

[External Email. Be cautious of content]

Rajesh,
Also you can change the service SID for a subset of prefixes using a policy, to apply a flex-algo for example, but you do not want to change the next-hop for each new service SID.

Mustapha.

From: spring <spring-bounces@ietf.org<mailto:spring-bounces@ietf.org>> On Behalf Of Rabadan, Jorge (Nokia - US/Mountain View)
Sent: Monday, July 19, 2021 9:47 AM
To: Rajesh M <mrajesh@juniper.net<mailto:mrajesh@juniper.net>>; Rajesh M <mrajesh=40juniper.net@dmarc.ietf.org<mailto:mrajesh=40juniper.net@dmarc.ietf.org>>; Ketan Talaulikar (ketant) <ketant@cisco.com<mailto:ketant@cisco.com>>; gdawra.ietf@gmail.com<mailto:gdawra.ietf@gmail.com>; Clarence Filsfils (cfilsfil) <cfilsfil@cisco.com<mailto:cfilsfil@cisco.com>>; robert@raszuk.net<mailto:robert@raszuk.net>; bruno.decraene@orange.com<mailto:bruno.decraene@orange.com>
Cc: spring@ietf.org<mailto:spring@ietf.org>; bgp@ans.net<mailto:bgp@ans.net>; Srihari Sangli <ssangli@juniper.net<mailto:ssangli@juniper.net>>; Shraddha Hegde <shraddha@juniper.net<mailto:shraddha@juniper.net>>; bess@ietf.org<mailto:bess@ietf.org>
Subject: Re: [spring] SRv6 BGP based Overlay Services (draft-ietf-bess-srv6-services-07)

Hi Rajesh,

The draft is written so that the next-hop address MAY be covered by the locator, but there are cases in which the next-hop address is not part of the locator prefix, and there are implementations already allowing that, so I don't agree the document should mandate what you are suggesting.

Thanks.
Jorge

From: Rajesh M <mrajesh@juniper.net<mailto:mrajesh@juniper.net>>
Date: Monday, July 19, 2021 at 3:24 PM
To: Rajesh M <mrajesh=40juniper.net@dmarc.ietf.org<mailto:mrajesh=40juniper.net@dmarc.ietf.org>>, Ketan Talaulikar (ketant) <ketant@cisco.com<mailto:ketant@cisco.com>>, gdawra.ietf@gmail.com<mailto:gdawra.ietf@gmail.com> <gdawra.ietf@gmail.com<mailto:gdawra.ietf@gmail.com>>, Clarence Filsfils (cfilsfil) <cfilsfil@cisco.com<mailto:cfilsfil@cisco.com>>, robert@raszuk.net<mailto:robert@raszuk.net> <robert@raszuk.net<mailto:robert@raszuk.net>>, bruno.decraene@orange.com<mailto:bruno.decraene@orange.com> <bruno.decraene@orange.com<mailto:bruno.decraene@orange.com>>, Rabadan, Jorge (Nokia - US/Mountain View) <jorge.rabadan@nokia.com<mailto:jorge.rabadan@nokia.com>>
Cc: spring@ietf.org<mailto:spring@ietf.org> <spring@ietf.org<mailto:spring@ietf.org>>, bgp@ans.net<mailto:bgp@ans.net> <bgp@ans.net<mailto:bgp@ans.net>>, Shraddha Hegde <shraddha@juniper.net<mailto:shraddha@juniper.net>>, bess@ietf.org<mailto:bess@ietf.org> <bess@ietf.org<mailto:bess@ietf.org>>, Srihari Sangli <ssangli@juniper.net<mailto:ssangli@juniper.net>>
Subject: RE: SRv6 BGP based Overlay Services (draft-ietf-bess-srv6-services-07)
Hi Authors,

Please respond.

Thanks
Rajesh



Juniper Business Use Only
From: spring <spring-bounces@ietf.org<mailto:spring-bounces@ietf.org>> On Behalf Of Rajesh M
Sent: Thursday, July 15, 2021 4:36 PM
To: Ketan Talaulikar (ketant) <ketant@cisco.com<mailto:ketant@cisco.com>>; gdawra.ietf@gmail.com<mailto:gdawra.ietf@gmail.com>; Clarence Filsfils (cfilsfil) <cfilsfil@cisco.com<mailto:cfilsfil@cisco.com>>; robert@raszuk.net<mailto:robert@raszuk.net>; bruno.decraene@orange.com<mailto:bruno.decraene@orange.com>; jorge.rabadan@nokia.com<mailto:jorge.rabadan@nokia.com>
Cc: spring@ietf.org<mailto:spring@ietf.org>; bgp@ans.net<mailto:bgp@ans.net>; Shraddha Hegde <shraddha@juniper.net<mailto:shraddha@juniper.net>>; bess@ietf.org<mailto:bess@ietf.org>
Subject: [spring] SRv6 BGP based Overlay Services (draft-ietf-bess-srv6-services-07)

[External Email. Be cautious of content]

Hi All,

As per this draft, this is how resolution must work.

1)For Non Intent service Route:
if BGP next hop is not reachable return.
Resolve SRv6 Service SID for forwarding.

2)For Intent service Route (IGP Flex-Algo first then BGP CAR then SR Policy):
BGP next hop is not reachable return.
Resolve SRv6 Service SID for forwarding(To find IGP flex algo).if successfully resolves then return.
Resolve BGP next hop for forwarding (in case above is not success).


Using Service SID (overlay),for resolution is definitely not recommended.

Instead in case of srv6, we always resolve on BGP nexthop. This will be in line with BGP legacy.
In case of best effort/flex algo we must mandate user to set corresponding locator as BGP nexthop for srv6 routes.
I think this is a reasonable mandate.

Thanks
Rajesh


Juniper Business Use Only