Anycast SID for SRv6 Path Egress Protection?) draft-hu-rtgwg-srv6-egress-protection

Huaimo Chen <huaimo.chen@futurewei.com> Thu, 21 November 2019 08:47 UTC

Return-Path: <huaimo.chen@futurewei.com>
X-Original-To: rtgwg@ietfa.amsl.com
Delivered-To: rtgwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id E18A212086C; Thu, 21 Nov 2019 00:47:27 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.998
X-Spam-Level:
X-Spam-Status: No, score=-1.998 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_NONE=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=futurewei.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 ojPc7DxrZU4O; Thu, 21 Nov 2019 00:47:25 -0800 (PST)
Received: from NAM05-DM3-obe.outbound.protection.outlook.com (mail-eopbgr730118.outbound.protection.outlook.com [40.107.73.118]) (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 DC4DF12083E; Thu, 21 Nov 2019 00:47:23 -0800 (PST)
ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=ggik4dzI03YMyKrGTFl/35MT/zGnLoSe3vZpRyyuuUKYj3WpcD3QHYVb2j/Qh+JbKgm4EodVxITDus25hycNCp8ThiHv6N16vw/MzQM6bUr1SeZB82saiPfCt8eHPI/c9r09rLO9SOeu+kInRa8m9oAqPdpyfxaRGR2ktSIZm2KkjsxGWx8uBs9WvJToJYjZWpaAK/Goxt4YaDJ82Zaz0fuo50GFc/q5rQHAePr8nZ0XxiXTx271P1gUu7ynzTWG2k/Cu/VUgdeByTficmvtKBnBNgmYzgKZ6raj3i4av/HAD3krt2k1CKVdIQrNmDyfrCWHjsk4WR8inhFLPvsXtA==
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=t/XKfByOkOCU3fj848cJOmnxa4N1LRoaH4zETchehmw=; b=nTQD+F+689LyYGdNGRICxQxJVK3DagAzff+4syH5h8rYemrLyziLpbw7I6plpkKnvMoZVq+Y8Rh0eG8a98Mk67y5BK/Fq5ZN8MMiJk2fcC4MryrA6ZJ40uWq3bFy2ej58cac7emZ11N+w8bgSOcXDeMWG8TZau4yJFbutte7iJeTeiimkW0damX64sb274k1FeoN1yH8YCnFoFoaSz6ImbsZ4sK88t15BmqtBRxAGFDLq9Rih9sDtbwBvwgMb4hBvYx+/ZMcZmRtybVHNthwHCYjqMkbWNjCCD54d6UlHmw7FnarLOvdyJFdJ++LnkAJmZe4/anhRyMx82iis8CPaA==
ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=futurewei.com; dmarc=pass action=none header.from=futurewei.com; dkim=pass header.d=futurewei.com; arc=none
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Futurewei.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=t/XKfByOkOCU3fj848cJOmnxa4N1LRoaH4zETchehmw=; b=SOdtZsfF8XCuQjl3RCzLQUz2N/E3A4Vs3JIR5/ccNSPn6UoKRmKgz0448YnkkT7lW5J0lH+SxKx385hr8Mh7XdYQ6jWpSdHsDEshDzBE6HvVybtSTmadT7pQDblBvMS9NmCIy7mpaQaBIVRs23elVy2SGcB+zEF0yw6y3rwZg7U=
Received: from SN6PR13MB2271.namprd13.prod.outlook.com (52.135.93.160) by SN6PR13MB2478.namprd13.prod.outlook.com (52.135.95.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2474.11; Thu, 21 Nov 2019 08:47:19 +0000
Received: from SN6PR13MB2271.namprd13.prod.outlook.com ([fe80::9bf:4fee:33a1:266]) by SN6PR13MB2271.namprd13.prod.outlook.com ([fe80::9bf:4fee:33a1:266%7]) with mapi id 15.20.2474.015; Thu, 21 Nov 2019 08:47:19 +0000
From: Huaimo Chen <huaimo.chen@futurewei.com>
To: Shraddha Hegde <shraddha@juniper.net>, "rtgwg@ietf.org" <rtgwg@ietf.org>, "spring@ietf.org" <spring@ietf.org>
Subject: Anycast SID for SRv6 Path Egress Protection?) draft-hu-rtgwg-srv6-egress-protection
Thread-Topic: Anycast SID for SRv6 Path Egress Protection?) draft-hu-rtgwg-srv6-egress-protection
Thread-Index: AQHVoEhIZZshlkQq/ESHmy/rIRoNHg==
Date: Thu, 21 Nov 2019 08:47:19 +0000
Message-ID: <SN6PR13MB227121A631BD41EA7A33430FF24E0@SN6PR13MB2271.namprd13.prod.outlook.com>
References: <D496C972D1A13540A730720631EC73419CD57298@nkgeml514-mbx.china.huawei.com>, <BYAPR05MB39434013BF74921704E0C534D54F0@BYAPR05MB3943.namprd05.prod.outlook.com>, BC5F242D-55A1-40F8-A762-0B8A9377F951
In-Reply-To: BC5F242D-55A1-40F8-A762-0B8A9377F951
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
authentication-results: spf=none (sender IP is ) smtp.mailfrom=huaimo.chen@futurewei.com;
x-originating-ip: [2001:67c:370:128:8de0:6d83:d8b9:db12]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: d21c1889-6b1f-4000-3427-08d76e5f6b22
x-ms-traffictypediagnostic: SN6PR13MB2478:
x-microsoft-antispam-prvs: <SN6PR13MB2478267A283816C003BBD167F24E0@SN6PR13MB2478.namprd13.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:8273;
x-forefront-prvs: 0228DDDDD7
x-forefront-antispam-report: SFV:NSPM; SFS:(10019020)(4636009)(136003)(376002)(346002)(366004)(39840400004)(396003)(199004)(189003)(71190400001)(86362001)(105004)(25786009)(7736002)(81156014)(8936002)(66556008)(66446008)(446003)(66946007)(46003)(316002)(81166006)(6436002)(5660300002)(64756008)(55016002)(7696005)(186003)(110136005)(76176011)(9686003)(54896002)(14454004)(6116002)(66476007)(52536014)(1941001)(19627405001)(102836004)(2906002)(2201001)(2501003)(71200400001)(478600001)(33656002)(11346002)(256004)(14444005)(76116006)(6506007)(44832011)(74316002)(99286004)(8676002); DIR:OUT; SFP:1102; SCL:1; SRVR:SN6PR13MB2478; H:SN6PR13MB2271.namprd13.prod.outlook.com; FPR:; SPF:None; LANG:en; PTR:InfoNoRecords; A:1; MX:1;
received-spf: None (protection.outlook.com: futurewei.com does not designate permitted sender hosts)
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam: BCL:0;
x-microsoft-antispam-message-info: 0Hut5w/6Be77DilojKj/JY8Y59+aGnmH0zrdLkjEWPfiiTqrvz6zoHDcmdJErRdE8zVbTwN42iqMeuHKthFbuD4GKYInQevr6fp4RnSPszHXZzH6MdK0CQy5H3/gCja97FgXE82KP5Fd059Y8h79iuArQXdIU4Q3W0G/e91WMOTSEFswejfjyrau4xV1XkuCICsqGl6pegsIvq/8bJwsxgcqdWhhdQ0JE+8gpKN6obvIRoxgh3g/FyBOlSmuuSo9PbK7/OKIf4f1bOy3aFdYnsaMTibpnXgIoURJHWmkDWW9rl0QQmQp5ceaSAlZWtfrQrCmCcmCI/o0y4iwDzfkuTip9cCkze9iiemnoHSUuJk3sc94r0qa5MhYyB+oaQYSf9KrG4PcfRFj5N2c+RYLr+a+UQRyj4Ce1sW8Om4iuy9EPRpMEWWTvrbv/NTr2+l6
x-ms-exchange-transport-forked: True
Content-Type: multipart/alternative; boundary="_000_SN6PR13MB227121A631BD41EA7A33430FF24E0SN6PR13MB2271namp_"
MIME-Version: 1.0
X-OriginatorOrg: Futurewei.com
X-MS-Exchange-CrossTenant-Network-Message-Id: d21c1889-6b1f-4000-3427-08d76e5f6b22
X-MS-Exchange-CrossTenant-originalarrivaltime: 21 Nov 2019 08:47:19.3007 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 0fee8ff2-a3b2-4018-9c75-3a1d5591fedc
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: tq9TsnfgiKMJsZKAV69jHcS7Xu/xN6B1Wc8OlacheFTAFVniV+7d423DtY7KZGYmZiEoZwv/TnUFp2/gYj/PWg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN6PR13MB2478
Archived-At: <https://mailarchive.ietf.org/arch/msg/rtgwg/ePKPlC3s7toQlURA2cYCDft3O3U>
X-BeenThere: rtgwg@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Routing Area Working Group <rtgwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtgwg>, <mailto:rtgwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/rtgwg/>
List-Post: <mailto:rtgwg@ietf.org>
List-Help: <mailto:rtgwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtgwg>, <mailto:rtgwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 21 Nov 2019 08:47:28 -0000

Hi Shraddha,

    Thanks for your question about using anycast SID for SRv6 Path Egress Protection.

    There are a few issues on using anycast SID for SRv6 Path Egress Protection, which include:
    1) The (primary) egress (e.g., PE3 in the figure on page 2 presented in IETF 106) and the backup egress (e.g., PE4) need to be configured with the same locator and VPN SID.
    2) When the failure on the interface between the egress (e.g., PE3) and the CE (e.g., CE2) happens, the traffic may loop and get lost. The ingress (e.g., PE1) will send packets to the egress (e.g., PE3), which forwards the packets to the backup egress (e.g., PE4) through anycast SID. If the link cost between the egress (e.g., PE3) and the backup egress (e.g., PE4) is much bigger than others, the egress sends back the packets to P1, which sends the packets to the egress again (packets loop between P1 and PE3).
    3) BGP is unable to select its next hop, that is that whichever next hop (either PE3 or PE4) selected by BGP is overwritten by the IGP shortest path.

Best Regards,
Huaimo