Re: [Isis-wg] [Technical Errata Reported] RFC5309 (5007)

Alexander Vainshtein <Alexander.Vainshtein@ecitele.com> Mon, 01 May 2017 07:53 UTC

Return-Path: <Alexander.Vainshtein@ecitele.com>
X-Original-To: isis-wg@ietfa.amsl.com
Delivered-To: isis-wg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id E9604128CD5 for <isis-wg@ietfa.amsl.com>; Mon, 1 May 2017 00:53:35 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.07
X-Spam-Level:
X-Spam-Status: No, score=-4.07 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-2.8, RCVD_IN_SORBS_SPAM=0.5, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_DKIM_INVALID=0.01, T_FILL_THIS_FORM_SHORT=0.01, T_KAM_HTML_FONT_INVALID=0.01, URIBL_BLOCKED=0.001] autolearn=ham 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 tdK8UNt4n9Wp for <isis-wg@ietfa.amsl.com>; Mon, 1 May 2017 00:53:33 -0700 (PDT)
Received: from mail1.bemta5.messagelabs.com (mail1.bemta5.messagelabs.com [195.245.231.139]) (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 D2B61129B7D for <isis-wg@ietf.org>; Mon, 1 May 2017 00:50:17 -0700 (PDT)
Received: from [85.158.139.163] by server-3.bemta-5.messagelabs.com id 97/7B-02022-7B8E6095; Mon, 01 May 2017 07:50:15 +0000
X-Brightmail-Tracker: H4sIAAAAAAAAA1WTe0wTSRzHb3Z2tyuh3ggoPyom2jNGD0HwQTY a4yFR9w+9XC4xEeNdb6srrbaFdKspwWh9X4tWfIDaYIRIfOADoSg+eEjjA5RoQGOUWoyCUuUu GHMXJYqxy4ri/vWZ+Xzn95uZzHI4ZoDVcZLTIdltokXPRtEzp7yfmOwPs1mp59w/8m+ftWP+w 743mB/ov4D4Yn8T5u97CjT8+Y9VGr6p2YX5G4E+hr9bx/JbGv9nf4kStr+sZ4RXe0qQ0Bk6Rg kHPlQxwmVfSCM8rzUI5eX9lODacZP5jVvOmG3GHOdfjOm6/xadW1ZLOZ+G67ELeYopD4riaLI Dw0HvHaQMYsheCjZvvYXVwVMEDX8HImYEx5K5UH06xHoQx8WR6XCsJ0nJYHIYg3t/E6NkYkkG eI8HNQrHkflw9E0rVnkhlIT/oRSmyUQIBv+lFdaSFdC7vepL5wEEpf/5WUWMIAvgbNeBQUZkD Ly7fWZwMSbx0NF9dJCBECivu4dVHg2vuj4xSiFEChA8fF7IqkIPnso6jSKA7MLQ5j2nUcUS6O 1308pxgPwENeE/1EwJgs1bXLSaWQvdvR2aIa58cRGroQ4KetxeRhWJcGLXKUYVd1k4EWrA6mX oIPTAjVROhPCTekY9gw0K+9q/XMAoaDncTReiSb5hx/MNi/mGxdT5qVB69S2rchIcL+vFQ9x6 rYsaPl+KNBVosizZ10v25LTpKUa7OdvksIpmS3Ja6qwUqyTLYrZkEY1yysocazWKPMsfIt8l5 PVlBlACR+lHa29uZLNiRhpzVuWZRNlksK+zSHIAJXKcHrSPeiJulF3KlpyrzZbI2x7SwEXr47 TLFK2Vc0WrbM5W1W00QRevbVMEUYRpne3rsqG/oh2N08VqUWQjMdG5kt1qdnzvX6N4DuljtdV KlWizzfG1+utIYyrSeNMkWmnsEL8pnQttKFrTlXc//VIgf0pngz+j4P24ewk7l25qmxXoXADj x7Qm+zufBNPdUfWp0ybfsDQ3Zf5ZIRQ5R5IjV0x5tY9/b2ud8W5bs3G+4WRxwsLSeXJmX5bh0 CKxcXxikqFo4NeK9LL8NdyzsZXmDLamsaXmQb6DW2w1psxp2bdb3D87mM7radkkpv2M7bL4GT m+OBAQBAAA
X-Env-Sender: Alexander.Vainshtein@ecitele.com
X-Msg-Ref: server-5.tower-188.messagelabs.com!1493625005!105346340!1
X-Originating-IP: [52.41.248.36]
X-StarScan-Received:
X-StarScan-Version: 9.4.12; banners=ecitele.com,-,-
X-VirusChecked: Checked
Received: (qmail 13648 invoked from network); 1 May 2017 07:50:08 -0000
Received: from ec2-52-41-248-36.us-west-2.compute.amazonaws.com (HELO EUR01-VE1-obe.outbound.protection.outlook.com) (52.41.248.36) by server-5.tower-188.messagelabs.com with AES256-SHA256 encrypted SMTP; 1 May 2017 07:50:08 -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; bh=+Y1vKFhWEb4iTgRiQlBhZv64ep2fE73FtLKu1Mz3Q80=; b=YWycz8vyNgGEdneqxK18Gl8kQFDdMjBVPQK7zyBPfbvjvmkVFLrEn7J+j+lDeXkReAfMtPKvS6xqoWCUvq3kBpuxD+Bi1OgIvYGTTdEE8Mjq+wY5x5+JZjAa2WYxo7N6l8Pklh8AxdonzQMb8Y6uTUHrwVmytj4X3mcSFnnLCGY=
Received: from AM4PR03MB1713.eurprd03.prod.outlook.com (10.167.88.15) by AM4PR03MB1715.eurprd03.prod.outlook.com (10.167.88.17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1047.13; Mon, 1 May 2017 07:50:03 +0000
Received: from AM4PR03MB1713.eurprd03.prod.outlook.com ([fe80::dd45:832a:e658:e737]) by AM4PR03MB1713.eurprd03.prod.outlook.com ([fe80::dd45:832a:e658:e737%14]) with mapi id 15.01.1047.019; Mon, 1 May 2017 07:50:03 +0000
From: Alexander Vainshtein <Alexander.Vainshtein@ecitele.com>
To: "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>
CC: "isis-wg@ietf.org" <isis-wg@ietf.org>, RFC Errata System <rfc-editor@rfc-editor.org>, "Naiming Shen (naiming)" <naiming@cisco.com>, "alex.zinin@alcatel-lucent.com" <alex.zinin@alcatel-lucent.com>, "akatlas@gmail.com" <akatlas@gmail.com>, "db3546@att.com" <db3546@att.com>, "Alvaro Retana (aretana)" <aretana@cisco.com>, "chopps@chopps.org" <chopps@chopps.org>, "hannes@gredler.at" <hannes@gredler.at>
Thread-Topic: [Isis-wg] [Technical Errata Reported] RFC5309 (5007)
Thread-Index: AQHSwYoCxBhcZtgLd0CoSDR/tVhrP6Hd9k4AgAAWr1CAAEQmAIAAyIsg
Date: Mon, 1 May 2017 07:50:03 +0000
Message-ID: <AM4PR03MB1713D57C0046833F38BB4F699D140@AM4PR03MB1713.eurprd03.prod.outlook.com>
References: <20170430081555.026C1B8183C@rfc-editor.org> <bd426412060143b18b888f9fb9135728@XCH-ALN-001.cisco.com> <AM4PR03MB171368B3A0BC936159ABE14A9D150@AM4PR03MB1713.eurprd03.prod.outlook.com> <c8cbc9ccc7924bb59a6394978d757b54@XCH-ALN-001.cisco.com>
In-Reply-To: <c8cbc9ccc7924bb59a6394978d757b54@XCH-ALN-001.cisco.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [109.64.130.250]
x-microsoft-exchange-diagnostics: 1; AM4PR03MB1715; 7:RMwrtQf1K9+d6yI4O2LpvWYp1EcvW7pKR2hh4rWkHuwuc8uNXrcta5FpuVK0SCe2qBbhUuYULXp7CZE0mH4SOu/L/EH33RlfO5AmrHyyKltuLS05I+hv8ItSuaFZh93r9NRDn4hGjaa5zKeZoE5YtCFC5sAhNqIVLXUSvMf4vmUSNBMEKZB0alL0GneUW3QAzZZmzWAqgfmvU0t6LCi/jkiSS1DUaqEGAIA/kOsTNI2EcN/YYrHFOJH6F7ekN/TLOJQUGdYOKbpo66YjaJ5JH3+IjTN2E6UY6GJTx9zwKNOj+lH28g6ISnf2XSKayHkynDjPF4VFmJRYigSSjEjhVg==
x-ms-office365-filtering-correlation-id: 06eed099-0452-4709-869d-08d49066ad48
x-ms-office365-filtering-ht: Tenant
x-microsoft-antispam: UriScan:; BCL:0; PCL:0; RULEID:(22001)(2017030254075)(48565401081)(201703131423075)(201703031133081)(201702281549075); SRVR:AM4PR03MB1715;
x-microsoft-antispam-prvs: <AM4PR03MB1715FD751D5B3ADE25D9F7DC9D140@AM4PR03MB1715.eurprd03.prod.outlook.com>
x-exchange-antispam-report-test: UriScan:(97927398514766)(95692535739014)(21748063052155)(279101305709854);
x-exchange-antispam-report-cfa-test: BCL:0; PCL:0; RULEID:(6040450)(601004)(2401047)(8121501046)(5005006)(10201501046)(3002001)(93006095)(93001095)(6055026)(6041248)(20161123562025)(201703131423075)(201702281528075)(201703061421075)(20161123564025)(20161123555025)(20161123560025)(6072148); SRVR:AM4PR03MB1715; BCL:0; PCL:0; RULEID:; SRVR:AM4PR03MB1715;
x-forefront-prvs: 02945962BD
x-forefront-antispam-report: SFV:NSPM; SFS:(10019020)(39400400002)(39410400002)(39450400003)(39850400002)(39840400002)(51874003)(377454003)(51914003)(13464003)(85664002)(252514010)(6306002)(229853002)(6116002)(3846002)(54906002)(790700001)(102836003)(5660300001)(54896002)(8936002)(99286003)(110136004)(16799955002)(15188155005)(33656002)(189998001)(7696004)(7736002)(7416002)(6436002)(236005)(74316002)(55016002)(606005)(7906003)(5890100001)(5250100002)(9686003)(4326008)(6506006)(81166006)(2900100001)(6916009)(38730400002)(6246003)(3280700002)(8676002)(53546009)(54356999)(76176999)(2950100002)(50986999)(66066001)(25786009)(2906002)(39060400002)(93886004)(53936002)(86362001)(508600001)(966004)(3660700001); DIR:OUT; SFP:1102; SCL:1; SRVR:AM4PR03MB1715; H:AM4PR03MB1713.eurprd03.prod.outlook.com; FPR:; SPF:None; MLV:ovrnspm; PTR:InfoNoRecords; LANG:en;
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: multipart/alternative; boundary="_000_AM4PR03MB1713D57C0046833F38BB4F699D140AM4PR03MB1713eurp_"
MIME-Version: 1.0
X-OriginatorOrg: ecitele.com
X-MS-Exchange-CrossTenant-originalarrivaltime: 01 May 2017 07:50:03.2276 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 2c514a61-08de-4519-b4c0-921fef62c42a
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM4PR03MB1715
X-CFilter-Loop: Reflected
Archived-At: <https://mailarchive.ietf.org/arch/msg/isis-wg/evc2yoR0rvrOPSB_Snm7CnLHF7A>
Subject: Re: [Isis-wg] [Technical Errata Reported] RFC5309 (5007)
X-BeenThere: isis-wg@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: IETF IS-IS working group <isis-wg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/isis-wg>, <mailto:isis-wg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/isis-wg/>
List-Post: <mailto:isis-wg@ietf.org>
List-Help: <mailto:isis-wg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/isis-wg>, <mailto:isis-wg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 01 May 2017 07:53:36 -0000

Les,
Lots of thanks for the clarification.
I fully agree with you that configuring a pair of interfaces across a P2P link with IP addresses from different subnets should not be encouraged even if these interfaces operate as P2P from the POV of the routing protocol.

The problem is that the scenario I've described is quite real, and, AFAIK,  no standard explicitly says that it is not supported.

I also do not fully  understand  your usage of plural ("these RFCs") - I have been only asking about a correction in a single RFC -5309.

I see several ways to resolve the problem:

1.       Recognize the erratum and hold it for the update of 5309

2.       Explicitly state that numbered P2P-over-LAN interfaces must still configure the terminating interfaces of the LAN link with IPv4 addresses from the same subnet (could be another sort of update for 5309).

What would you suggest?

Regard, and lots of thanks in advance,
Sasha



Regards,
Sasha

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

From: Les Ginsberg (ginsberg) [mailto:ginsberg@cisco.com]
Sent: Sunday, April 30, 2017 10:44 PM
To: Alexander Vainshtein <Alexander.Vainshtein@ecitele.com>
Cc: isis-wg@ietf.org; RFC Errata System <rfc-editor@rfc-editor.org>rg>; Naiming Shen (naiming) <naiming@cisco.com>om>; alex.zinin@alcatel-lucent.com; akatlas@gmail.com; db3546@att.com; Alvaro Retana (aretana) <aretana@cisco.com>om>; chopps@chopps.org; hannes@gredler.at
Subject: RE: [Isis-wg] [Technical Errata Reported] RFC5309 (5007)

Sasha -

The language you are asking to be changed is in regards to ARP. I am saying allowing an adjacency to be formed on a numbered LAN with mismatched subnets is neither introduced nor altered by these RFCs .
What is introduced is the possibility of operating on an unnumbered LAN - which is why the RFCs speak to that.

If you want to ask that protocol base specifications discuss ARP issues when mismatched subnets are allowed (which I am NOT encouraging you to do) then you will be directing your comments at the correct documents.
Asking that of these RFCs is inappropriate.

   Les


From: Alexander Vainshtein [mailto:Alexander.Vainshtein@ecitele.com]
Sent: Sunday, April 30, 2017 8:51 AM
To: Les Ginsberg (ginsberg)
Cc: isis-wg@ietf.org<mailto:isis-wg@ietf.org>; RFC Errata System; Naiming Shen (naiming); alex.zinin@alcatel-lucent.com<mailto:alex.zinin@alcatel-lucent.com>; akatlas@gmail.com<mailto:akatlas@gmail.com>; db3546@att.com<mailto:db3546@att.com>; Alvaro Retana (aretana); chopps@chopps.org<mailto:chopps@chopps.org>; hannes@gredler.at<mailto:hannes@gredler.at>
Subject: RE: [Isis-wg] [Technical Errata Reported] RFC5309 (5007)


Les,

Lots of thanks for a prompt response.



As I see it, the difference between the P2P and LAN modes is essential for OSPF:

- If an OSPF interface is a LAN (broadcast) interface, there is a check of the same subnet for received Hello packets. If the received Hello packets do not pass this check, they are discarded and an error is reported via SNMP.

- However, if an OSPF interface is a P2P interface, then the subnet check on the Hello packets is bypassed  by design as defined in Section 10.5 of RFC 2328:



                     The generic input processing of OSPF packets will

        have checked the validity of the IP header and the OSPF packet

        header.  Next, the values of the Network Mask, HelloInterval,

        and RouterDeadInterval fields in the received Hello packet must

        be checked against the values configured for the receiving

        interface.  Any mismatch causes processing to stop and the

        packet to be dropped.  In other words, the above fields are

        really describing the attached network's configuration. However,

        there is one exception to the above rule: on point-to-point

        networks and on virtual links, the Network Mask in the received

        Hello Packet should be ignored.



I.e., having different subnets on two ends of a PPP link would not cause any problems for OSPF - the adjacency would be successfully recognized, it would progress to its FULL state, and unicast traffic would cross such a link without any problem.



But if we have a P2P-over-LAN link (which is the case for RFC 5309), the result would be quite different - unless the ARP implementations go beyond what 5309 says and relax the check for all such links, be they numbered or unnumbered.



Do I miss something substantial here?







Regards,

Sasha



Office: +972-39266302

Cell:      +972-549266302

Email:   Alexander.Vainshtein@ecitele.com<mailto:Alexander.Vainshtein@ecitele.com>





-----Original Message-----
From: Les Ginsberg (ginsberg) [mailto:ginsberg@cisco.com]
Sent: Sunday, April 30, 2017 5:19 PM
To: RFC Errata System <rfc-editor@rfc-editor.org<mailto:rfc-editor@rfc-editor.org>>; Naiming Shen (naiming) <naiming@cisco.com<mailto:naiming@cisco.com>>; alex.zinin@alcatel-lucent.com<mailto:alex.zinin@alcatel-lucent.com>; akatlas@gmail.com<mailto:akatlas@gmail.com>; db3546@att.com<mailto:db3546@att.com>; Alvaro Retana (aretana) <aretana@cisco.com<mailto:aretana@cisco.com>>; chopps@chopps.org<mailto:chopps@chopps.org>; hannes@gredler.at<mailto:hannes@gredler.at>
Cc: Alexander Vainshtein <Alexander.Vainshtein@ecitele.com<mailto:Alexander.Vainshtein@ecitele.com>>; isis-wg@ietf.org<mailto:isis-wg@ietf.org>
Subject: RE: [Isis-wg] [Technical Errata Reported] RFC5309 (5007)



Alexander -



I am not speaking for the RFC authors, but regarding your point:



> o          Are assigned with IP addresses and subnet masks yielding different

> subnets



I fail to see why this issue is unique to (or associated with) running in P2P mode.



The unnumbered case is specifically mentioned because in such a case it can be expected that the next hop address will be a loopback address and therefore there will be no common subnet.

But in the numbered case whether you have one neighbor in P2P mode or many neighbors in multi-access mode the msimatched subnet issue is the same. Therefore I see no reason why these RFCs should discuss it.



???



   Les





> -----Original Message-----

> From: Isis-wg [mailto:isis-wg-bounces@ietf.org] On Behalf Of RFC

> Errata System

> Sent: Sunday, April 30, 2017 1:16 AM

> To: Naiming Shen (naiming); alex.zinin@alcatel-lucent.com<mailto:alex.zinin@alcatel-lucent.com>;

> akatlas@gmail.com<mailto:akatlas@gmail.com>; db3546@att.com<mailto:db3546@att.com>; Alvaro Retana (aretana);

> chopps@chopps.org<mailto:chopps@chopps.org>; hannes@gredler.at<mailto:hannes@gredler.at>

> Cc: Alexander.Vainshtein@ecitele.com<mailto:Alexander.Vainshtein@ecitele.com>; isis-wg@ietf.org<mailto:isis-wg@ietf.org>;

> rfc-editor@rfc- editor.org

> Subject: [Isis-wg] [Technical Errata Reported] RFC5309 (5007)

>

> The following errata report has been submitted for RFC5309,

> "Point-to-Point Operation over LAN in Link State Routing Protocols".

>

> --------------------------------------

> You may review the report below and at:

> http://www.rfc-editor.org/errata_search.php?rfc=5309&eid=5007

>

> --------------------------------------

> Type: Technical

> Reported by: Alexander Vainshtein <Alexander.Vainshtein@ecitele.com<mailto:Alexander.Vainshtein@ecitele.com>>

>

> Section: 4.3

>

> Original Text

> -------------

> For the ARP implementation (which checks that the subnet of the source

> address of the ARP request matches the local interface address), this

> check needs to be relaxed for the unnumbered p2p-over-lan circuits.

>

> Corrected Text

> --------------

> For the ARP implementation (which checks that the subnet of the source

> address of the ARP request matches the local interface address), this

> check needs to be relaxed for the p2p-over-lan circuits (both numbered

> and unnumbered).

>

> Notes

> -----

> Consider the following situation:

> 1.         Two routers, R1 and R2, are connected by a physical P2P  Ethernet

> link

> 2.         OSPFv2 is enabled on the interfaces representing the endpoints of

> this link.

> 3.      From the OSPF POV these interfaces:

> o          Are configured as P2P

> o          Belong to the same area

> o          Are assigned with IP addresses and subnet masks yielding different

> subnets

> 4.    ARP check mentioned in the problematic text is not relaxed.

>

> Under this conditions:

> -Both R1 and R2 will accept Hello messages sent by the other router

> (becase it ignores subnet in Hello messages received via P2P

> interfaces)

> - Adjacency between R1 and R2 will progress to FULL state (because all

> OSPFv2 messages will be sent with AllSPFRouters multicast IPv4

> address)

> - Unicast traffic sent by R1 to R2 (and vice versa) will be blackholed

> because ARP will not resolve addresses assigned to the corresponding interfaces.

>

> Instructions:

> -------------

> This erratum is currently posted as "Reported". If necessary, please

> use "Reply All" to discuss whether it should be verified or rejected.

> When a decision is reached, the verifying party can log in to change

> the status and edit the report, if necessary.

>

> --------------------------------------

> RFC5309 (draft-ietf-isis-igp-p2p-over-lan-06)

> --------------------------------------

> Title               : Point-to-Point Operation over LAN in Link State Routing

> Protocols

> Publication Date    : October 2008

> Author(s)           : N. Shen, Ed., A. Zinin, Ed.

> Category            : INFORMATIONAL

> Source              : IS-IS for IP Internets

> Area                : Routing

> Stream              : IETF

> Verifying Party     : IESG

>

> _______________________________________________

> Isis-wg mailing list

> Isis-wg@ietf.org<mailto:Isis-wg@ietf.org>

> https://www.ietf.org/mailman/listinfo/isis-wg

___________________________________________________________________________

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.
___________________________________________________________________________