Re: [netmod] Doubts about static routes in RFC 8349 (was: Doubts about static routes in RFC 8022)

Alexander Vainshtein <Alexander.Vainshtein@ecitele.com> Wed, 03 April 2019 07:13 UTC

Return-Path: <Alexander.Vainshtein@ecitele.com>
X-Original-To: netmod@ietfa.amsl.com
Delivered-To: netmod@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8C4EF120086; Wed, 3 Apr 2019 00:13:15 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.699
X-Spam-Level:
X-Spam-Status: No, score=-1.699 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_INVALID=0.1, DKIM_SIGNED=0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=fail (1024-bit key) reason="fail (body has been altered)" header.d=eci365.onmicrosoft.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 5vvEK_6I5y_j; Wed, 3 Apr 2019 00:13:12 -0700 (PDT)
Received: from mail1.bemta25.messagelabs.com (mail1.bemta25.messagelabs.com [195.245.230.4]) (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 476D21200D7; Wed, 3 Apr 2019 00:13:10 -0700 (PDT)
Received: from [46.226.52.103] (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256 bits)) by server-4.bemta.az-a.eu-west-1.aws.symcld.net id EE/67-23897-40D54AC5; Wed, 03 Apr 2019 07:13:08 +0000
X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrCJsWRWlGSWpSXmKPExsViovlDRZc5dkm MwdPn6haT385jtriwai6bxfyLjawWF978ZnZg8ZjyeyOrx5IlP5k8Nl2+wxjAHMWamZeUX5HA mtG69RJ7QddzxorHPUINjH8eM3YxcnGwCCxilvi68xBzFyMnh5BAP5PE+WcxIAkhgXuMEn/ff mEFSbAJ2EpsWn2XDcQWEfCSmLP0IAuIzQxkN3/qZAexhQWSJG5e6WOEqEmWWH79BZRtJbH06H uwBSwCKhL9fbOAZnJw8ArESnycKg6xq59R4ueEtWD1nEC7TnY9ArMZBcQkvp9awwSxS1zi1pP 5YLaEgIDEkj3nmSFsUYmXj/+xQtQnSdx/upARIq4oMePeHHYIW1bi0vxuqLivxMHzDSwgN0gI KEtseRELcoOEwC1GiZsLT7BCxLUkvt5NgyiXkjhx8SgrhJ0j0dtwEGqkjMTStTsYIXrnsUkcv H+YDRKIyRIn5nxmgSiSk1jV+5AFougCs8TGGxCPMQvkSXS9XcI4gVFzFpLfZiFJgdi8AoISJ2 c+YZkFdBOzgKbE+l36ECWKElO6H7JD2BoSrXPmsiOLL2BkX8VonlSUmZ5RkpuYmaNraGCga2h opGtoaaprbqaXWKWbqJdaqlueWlyia6iXWF6sV1yZm5yTopeXWrKJEZjSUgoO++xgvLc8/RCj JAeTkijvYpMlMUJ8SfkplRmJxRnxRaU5qcWHGGU4OJQkeN2jgXKCRanpqRVpmTnA5AqTluDgU RLhLQJJ8xYXJOYWZ6ZDpE4xunIcWPRwLjNH38ZnQHLLfRC5C0y+Pfh8LrMQS15+XqqUOG8eSL MASHNGaR7caFhmuMQoKyXMy8jAwCDEU5BalJtZgir/ilGcg1FJmHcGyBSezLwSuAteAR3HBHS cRel8kONKEhFSUg2Mcfltu8ujtqxpuXb78/nHmi+ePtYwF2mdUCT1/Ndla/2AaY8ylnr8004P mMqrpuZfvmnZdc7u6Qu5T+TVTnlhV6UuckGX793mkxFzO9ruVDm3XfyYqze9/9v0TMV/N9ptr 156VcFs7he86lT0pT+2qYrJn+7HZTrvCvm3WPPFutneOkrNmx6pKrEUZyQaajEXFScCAEXBXA gHBAAA
X-Env-Sender: Alexander.Vainshtein@ecitele.com
X-Msg-Ref: server-5.tower-267.messagelabs.com!1554275584!5052283!1
X-Originating-IP: [52.41.248.36]
X-SYMC-ESS-Client-Auth: mailfrom-relay-check=pass
X-StarScan-Received:
X-StarScan-Version: 9.31.5; banners=ecitele.com,-,-
X-VirusChecked: Checked
Received: (qmail 1841 invoked from network); 3 Apr 2019 07:13:06 -0000
Received: from us-west-2a.mta.dlp.protect.symantec.com (HELO EUR03-DB5-obe.outbound.protection.outlook.com) (52.41.248.36) by server-5.tower-267.messagelabs.com with AES256-SHA256 encrypted SMTP; 3 Apr 2019 07:13:06 -0000
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ECI365.onmicrosoft.com; s=selector1-ecitele-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=Yb78EqFHwKdIlFH3AqLtwLuCBNtlnh4XuV6o8LfCMwg=; b=YR3PaMMwZSxwGvnYx00C4niQOS6RrgCKzkkyAjbtwfFKxxf34w9edT3t4F3CkL1sx6adVuZcF7Kkd5JbzNDB9cRzjRlXzcJUlOgblxnZTIkxmiKWvBo+VV81vAc/MfAEAi0V8KFwnJafvjol8pSl+SNK1UyJwj92wWGU172Z8PY=
Received: from AM0PR03MB3828.eurprd03.prod.outlook.com (52.135.146.159) by AM0PR03MB6020.eurprd03.prod.outlook.com (10.255.31.13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1750.17; Wed, 3 Apr 2019 07:13:02 +0000
Received: from AM0PR03MB3828.eurprd03.prod.outlook.com ([fe80::7946:b505:a799:7a25]) by AM0PR03MB3828.eurprd03.prod.outlook.com ([fe80::7946:b505:a799:7a25%3]) with mapi id 15.20.1750.017; Wed, 3 Apr 2019 07:13:02 +0000
From: Alexander Vainshtein <Alexander.Vainshtein@ecitele.com>
To: "Acee Lindem (acee)" <acee@cisco.com>, "lhotka@nic.cz" <lhotka@nic.cz>
CC: "rtgwg@ietf.org" <rtgwg@ietf.org>, "netmod@ietf.org" <netmod@ietf.org>
Thread-Topic: Doubts about static routes in RFC 8349 (was: Doubts about static routes in RFC 8022)
Thread-Index: AdTpW2iLlm1nfHS0SZq0IWkeRjQi6P//7NcA//7QGDA=
Date: Wed, 3 Apr 2019 07:13:02 +0000
Message-ID: <AM0PR03MB38286521B6CDFD36D173C6889D570@AM0PR03MB3828.eurprd03.prod.outlook.com>
References: <AM0PR03MB3828CD6E93236076142079109D560@AM0PR03MB3828.eurprd03.prod.outlook.com> <399C7547-D8A6-4938-B5F2-9F6F7DFA795B@cisco.com>
In-Reply-To: <399C7547-D8A6-4938-B5F2-9F6F7DFA795B@cisco.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [147.234.241.1]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: f8609cb1-5d42-4ef8-aaf1-08d6b803cfae
x-ms-office365-filtering-ht: Tenant
x-microsoft-antispam: BCL:0; PCL:0; RULEID:(2390118)(7020095)(4652040)(8989299)(5600139)(711020)(4605104)(4618075)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(2017052603328)(7193020); SRVR:AM0PR03MB6020;
x-ms-traffictypediagnostic: AM0PR03MB6020:
x-ms-exchange-purlcount: 1
x-microsoft-antispam-prvs: <AM0PR03MB6020E917B0B54782DB6E873E9D570@AM0PR03MB6020.eurprd03.prod.outlook.com>
x-forefront-prvs: 0996D1900D
x-forefront-antispam-report: SFV:NSPM; SFS:(10019020)(346002)(376002)(396003)(136003)(366004)(39860400002)(51874003)(53754006)(189003)(199004)(53546011)(110136005)(72206003)(71200400001)(55016002)(6506007)(6306002)(102836004)(236005)(486006)(99286004)(52536014)(54906003)(106356001)(9686003)(7696005)(26005)(446003)(66066001)(71190400001)(97736004)(186003)(54896002)(76176011)(316002)(7736002)(105586002)(81156014)(25786009)(74316002)(606006)(33656002)(11346002)(68736007)(5660300002)(476003)(81166006)(8676002)(478600001)(8936002)(6116002)(14444005)(256004)(6436002)(53936002)(3846002)(6246003)(790700001)(229853002)(4326008)(86362001)(14454004)(2906002)(2501003); DIR:OUT; SFP:1102; SCL:1; SRVR:AM0PR03MB6020; H:AM0PR03MB3828.eurprd03.prod.outlook.com; FPR:; SPF:None; LANG:en; PTR:InfoNoRecords; MX:1; A:1;
received-spf: None (protection.outlook.com: ecitele.com does not designate permitted sender hosts)
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam-message-info: lUtFEP7xjwWib9DGpPsI6gE70Y6ty44udrGdFzjmTcbLgyw36Vj0NT9nxDPYOrvmJD9BhxPK1NziGpDGqYnUM8VArtsw1KDwbaqxPMqjZ/LcCry8NnbSpIeMfc06TpqPCw/PHSQeUyme7hfXhkS71U/tqGpWhkVxLm4I8DbiDsPL8k+PDAeou6fydlTzU4I/MIRkvGFPB5HkXVjHOwSsjXmqTg1SEOVer7KOU5fdtotJ4DdtsehRe6v2Ot17HCK2VESVUwkJlcVFspW6NTVbksfJNYXX5kRHRU2GpMhTttUtfydj6T4a52LRHBDc6NH+Ce2HAeDicCWH0Na8RzgZ8y5MlKvCByEYEtuFXTFGcA7kWhqF+zZVoVE8btavEXB7iLIdoCb39S5lRDVlFHFHAb12rP/fzJflkaax/MIXOAU=
Content-Type: multipart/alternative; boundary="_000_AM0PR03MB38286521B6CDFD36D173C6889D570AM0PR03MB3828eurp_"
MIME-Version: 1.0
X-OriginatorOrg: ecitele.com
X-MS-Exchange-CrossTenant-Network-Message-Id: f8609cb1-5d42-4ef8-aaf1-08d6b803cfae
X-MS-Exchange-CrossTenant-originalarrivaltime: 03 Apr 2019 07:13:02.6205 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 2c514a61-08de-4519-b4c0-921fef62c42a
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM0PR03MB6020
X-CFilter-Loop: Reflected
Archived-At: <https://mailarchive.ietf.org/arch/msg/netmod/yQzYBlwKTl04NiptVmh080j3Zq0>
Subject: Re: [netmod] Doubts about static routes in RFC 8349 (was: Doubts about static routes in RFC 8022)
X-BeenThere: netmod@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: NETMOD WG list <netmod.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/netmod>, <mailto:netmod-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/netmod/>
List-Post: <mailto:netmod@ietf.org>
List-Help: <mailto:netmod-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/netmod>, <mailto:netmod-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 03 Apr 2019 07:13:16 -0000

Acee,
Lots of thanks for a prompt response with a highly relevant pointer.

I will read draft-ietf-rtgwg-yang-rib-extend<https://tools.ietf.org/html/draft-ietf-rtgwg-yang-rib-extend-01> and probably send more questions.

Meanwhile, could you please explain the rationale for changing the data model that has been defined in RFC 4292 (where both the destination prefix and the next hop have been parts of the index in the appropriate MIB table) ?

The side effect of this change is  that it is not backward-compatible with multiple existing RFC 4292-compliant RIB implementations:

-          Retrieval of such a RIB using YANG requires a stateful mapper that merges multiple RIB entries with the same destination prefix and different “simple” NH into a single entry with the next-hop-list

-          Configuration of a single static route that uses the next-hop-list requires a mapper that splits such a list into multiple 4292-compliant routes (simpler than merge, but still non-trivial IMHO).

Regards,
Sasha

Office: +972-39266302
Cell:      +972-549266302
Email:   Alexander.Vainshtein@ecitele.com

From: Acee Lindem (acee) <acee@cisco.com>;
Sent: Tuesday, April 2, 2019 7:45 PM
To: Alexander Vainshtein <Alexander.Vainshtein@ecitele.com>;; lhotka@nic.cz
Cc: rtgwg@ietf.org; netmod@ietf.org
Subject: Re: Doubts about static routes in RFC 8349 (was: Doubts about static routes in RFC 8022)

Hi Sasha,
You are correct that there is no per-next-hop preference in the current model. However, this is included in the augmentation in draft-ietf-rtgwg-yang-rib-extend.
Thanks,
Acee

From: Alexander Vainshtein <Alexander.Vainshtein@ecitele.com<mailto:Alexander.Vainshtein@ecitele.com>>
Date: Tuesday, April 2, 2019 at 9:53 AM
To: Acee Lindem <acee@cisco.com<mailto:acee@cisco.com>>, Ladislav Lhotka <lhotka@nic.cz<mailto:lhotka@nic.cz>>
Cc: Routing WG <rtgwg@ietf.org<mailto:rtgwg@ietf.org>>, "netmod@ietf.org<mailto:netmod@ietf.org>" <netmod@ietf.org<mailto:netmod@ietf.org>>
Subject: Doubts about static routes in RFC 8349 (was: Doubts about static routes in RFC 8022)

Hi all,
I have noticed that 8022 has been obsoleted by RFC 8349. But it has exactly the same problem.

Regards,
Sasha

Office: +972-39266302
Cell:      +972-549266302
Email:   Alexander.Vainshtein@ecitele.com<mailto:Alexander.Vainshtein@ecitele.com>

From: Alexander Vainshtein
Sent: Tuesday, April 2, 2019 3:57 PM
To: 'acee@cisco.com'; <acee@cisco.com<mailto:acee@cisco.com>>; 'lhotka@nic.cz'; <lhotka@nic.cz<mailto:lhotka@nic.cz>>
Cc: 'rtgwg@ietf.org'; <rtgwg@ietf.org<mailto:rtgwg@ietf.org>>; 'netmod@ietf.org'; <netmod@ietf.org<mailto:netmod@ietf.org>>
Subject: Doubts about static routes in RFC 8022
Importance: High

Acee, Ladislav and all,
I have serious doubts regarding the data model for static routes in RFC 8022.

As I see it, the data model defined in this document does not support multiple routes with common destination, different next hops and different route preferences.

This is because only route destination is considered as the key in the RIB in Appendix A of RFC 8022., while route preference is a per-route read-only leaf in the data model.

In particular (and this was my original problem) , it is possible to configure a static route with multiple next hops (using the next-hop-list construct) using the data model defined in RFC 8022, but all the next hops in this construct would have the same preference. AFAIK, many (if not all) deployed implementations support ability to configure static routes with the same destination, different next hops and different preferences, so that one of these next hops would act as a protection of the other.

For the reference, this problem does not exist in the standard MIB for the RIB (RFC 4292), because it includes both the route destination and its next hop in the list  of indices in the corresponding MIB.

What, if anything, did I miss?

Regards, and lots of thanks in advance,
Sasha

Office: +972-39266302
Cell:      +972-549266302
Email:   Alexander.Vainshtein@ecitele.com<mailto:Alexander.Vainshtein@ecitele.com>


___________________________________________________________________________

This e-mail message is intended for the recipient only and contains information which is
CONFIDENTIAL and which may be proprietary to ECI Telecom. If you have received this
transmission in error, please inform us by e-mail, phone or fax, and then delete the original
and all copies thereof.
___________________________________________________________________________

___________________________________________________________________________

This e-mail message is intended for the recipient only and contains information which is 
CONFIDENTIAL and which may be proprietary to ECI Telecom. If you have received this 
transmission in error, please inform us by e-mail, phone or fax, and then delete the original 
and all copies thereof.
___________________________________________________________________________