IETF Logo Mail Archive

Re: [v6ops] [dhcwg] IPv6-Only Preferred DHCPv4 option

"Bernie Volz (volz)" <volz@cisco.com> Fri, 06 December 2019 14:59 UTC

Return-Path: <volz@cisco.com>
X-Original-To: v6ops@ietfa.amsl.com
Delivered-To: v6ops@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 25D8B1200C5; Fri, 6 Dec 2019 06:59:43 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.499
X-Spam-Level:
X-Spam-Status: No, score=-14.499 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_HI=-5, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cisco.com header.b=E/DH1HQs; dkim=pass (1024-bit key) header.d=cisco.onmicrosoft.com header.b=MY4eK9Lu
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 mrenV3qzStyM; Fri, 6 Dec 2019 06:59:41 -0800 (PST)
Received: from alln-iport-4.cisco.com (alln-iport-4.cisco.com [173.37.142.91]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id B9DA4120020; Fri, 6 Dec 2019 06:59:40 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=13080; q=dns/txt; s=iport; t=1575644380; x=1576853980; h=from:to:cc:subject:date:message-id:references: in-reply-to:mime-version; bh=xL2peSIRampG9UM4GLNi9YQ+ZOPjymK12o0iCCKrr5I=; b=E/DH1HQsAKRCuEDBgb7sXyI2W8nuOFOt9NrdNGqsdJc24jdjZgIMhAx5 g7+OoTZarQnOPBYgAZH57VdhEWtxlz7GM67lHjpweVtVVwAi0f0E0h0ZL tJh2rlifvMU3hUyZl5cSRkkOuXo1tbJis8YBvq+qWORnMJlJV8V3nc7Xs A=;
IronPort-PHdr: 9a23:9K6eqxCWkAIVXdY84DlLUyQJPHJ1sqjoPgMT9pssgq5PdaLm5Zn5IUjD/qgw3kTRU9Dd7PRJw6rNvqbsVHZIwK7JsWtKMdRXUgMdz8AfngguGsmAXFP8KOzCZC0hF8MEX1hgrDm2
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: A0CuBQCibOpd/5RdJa1bCRwBAQEBAQcBAREBBAQBAYF+gRwvJCwFbFggBAsqCoQhg0YDin6CX4lbiUeEYoFCgRADVAkBAQEMAQEtAgEBhEACF4F+JDgTAgMNAQEEAQEBAgEFBG2FNwyFUgEBAQEDEhEKEwEBNwEPAgEIEQQBASgDAgICHxEUCQgCBAENBQgagwGBeU0DLgECohkCgTiIYHWBMoJ+AQEFhRoNC4IXCYE2jBcaggCBEUeCTD6CG4F7AQgKAQkYNIJaMoIskCGFTySXeEIKgi6RP4Q2miaOSopXj0wCBAIEBQIOAQEFgWkiZ3FwFTuCbFARFIxmg3OKU3SBKI4OgSIBgQ8BAQ
X-IronPort-AV: E=Sophos;i="5.69,285,1571702400"; d="scan'208,217";a="378469421"
Received: from rcdn-core-12.cisco.com ([173.37.93.148]) by alln-iport-4.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 06 Dec 2019 14:59:30 +0000
Received: from XCH-ALN-007.cisco.com (xch-aln-007.cisco.com [173.36.7.17]) by rcdn-core-12.cisco.com (8.15.2/8.15.2) with ESMTPS id xB6ExUQ5006559 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=FAIL); Fri, 6 Dec 2019 14:59:30 GMT
Received: from xhs-aln-001.cisco.com (173.37.135.118) by XCH-ALN-007.cisco.com (173.36.7.17) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 6 Dec 2019 08:59:29 -0600
Received: from xhs-rtp-002.cisco.com (64.101.210.229) by xhs-aln-001.cisco.com (173.37.135.118) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 6 Dec 2019 08:59:29 -0600
Received: from NAM04-BN3-obe.outbound.protection.outlook.com (64.101.32.56) by xhs-rtp-002.cisco.com (64.101.210.229) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Fri, 6 Dec 2019 09:59:29 -0500
ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=GCd6CcbwYqi2OqIqe54YGqcrI8BTIj6NlRFSHF2XoEBR5v2XLicEEU7yPO6dN3aqJKQMmjxr3ufkd+8H9e/sjHsWMDXEgBJcsKZavckbHsHR2wLYlqCp3QwXYTAVK7NIet0OONcpkgdkHkXFcxGl3093BRx739CWCO0sBjtM8iVBukolIeEW5rnu4LfM/McJQn3j+IwGnpXbLyotjaZZZifEA6RyaSg/9/7u28HoA+9E6461xG70QLPskH2omSx2HHNafw8spff6MRzkAskwPxBp/UNdQ8M0xzKqzqHiMtedNvEbP4uJid1+VDE+K7i8QDIMJ6556VBqjz7j8yp9oA==
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=xL2peSIRampG9UM4GLNi9YQ+ZOPjymK12o0iCCKrr5I=; b=S1nN7IldhVPNEydGreRve7lhKdFi6ItnXRMgc4+bsjXrr+Mhu2fRxbuJaTjKtKCeZUL5kTM2c/KyJQEoOlkLUnK9ZCSvmHeZGcC5/xphsN8Nnfq8c+I2NOb+1aidRnE5XtrnFATvqdFTJUkGlNGIlZKFq3DinQx4WIu5u1ccJDUsen12CqKNx62U2ImyOFMUdJW8vAv2N7WstyN11hHSOeZsFCV72HJrOK2HLsg5B13Gm4+5/IQvpOIbdOF4xS64gl1uAWQ6IPiNDdrNsutFjyV+Hq8YVRc0y2X2JYtMJnaHm9pp7feQdNkDjQQ0gpjIEjic8vBQWadsHAMYsrjWJA==
ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=cisco.com; dmarc=pass action=none header.from=cisco.com; dkim=pass header.d=cisco.com; arc=none
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cisco.onmicrosoft.com; s=selector2-cisco-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=xL2peSIRampG9UM4GLNi9YQ+ZOPjymK12o0iCCKrr5I=; b=MY4eK9Lupq11PAoUgp2JFZEWYjX0WZ89h1VSdT2B4FLSjmRbBmlLZC3URf31fcegwK7gzlLjI+3VharbZpA2X4rQ3lEb0wsolLXSK5yqIdC5j2lQJeiyoyGWv1RdzZHG40/pEixAxC2qrgqs1hb1OAn5LmriHzJR4qVQoZnPF7U=
Received: from DM6PR11MB4137.namprd11.prod.outlook.com (20.176.126.158) by DM6PR11MB4220.namprd11.prod.outlook.com (52.132.251.218) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2516.14; Fri, 6 Dec 2019 14:59:28 +0000
Received: from DM6PR11MB4137.namprd11.prod.outlook.com ([fe80::4194:dade:1d47:2678]) by DM6PR11MB4137.namprd11.prod.outlook.com ([fe80::4194:dade:1d47:2678%6]) with mapi id 15.20.2516.017; Fri, 6 Dec 2019 14:59:28 +0000
From: "Bernie Volz (volz)" <volz@cisco.com>
To: Lorenzo Colitti <lorenzo=40google.com@dmarc.ietf.org>, Jen Linkova <furry13@gmail.com>, Tomek Mrugalski <tomasz.mrugalski@gmail.com>
CC: V6 Ops List <v6ops@ietf.org>, "draft-link-dhc-v6only@ietf.org" <draft-link-dhc-v6only@ietf.org>, "dhcwg@ietf.org" <dhcwg@ietf.org>, Michael Richardson <mcr+ietf@sandelman.ca>
Thread-Topic: [v6ops] [dhcwg] IPv6-Only Preferred DHCPv4 option
Thread-Index: AQHVrEXBZ9rqhGZ/IUaWcKhj5j3PcA==
Date: Fri, 06 Dec 2019 14:59:28 +0000
Message-ID: <DM6PR11MB4137A537075D4D90732F7EB4CF5F0@DM6PR11MB4137.namprd11.prod.outlook.com>
References: <CAFU7BAR1JLUZps=CAqJfeQtUf-xQ88RYvgYrPCP+QP0Ter7YFg@mail.gmail.com> <E03BBE6C-3BED-4D49-8F79-0A1B313EFD9D@apple.com> <28594.1575483729@localhost> <CAFU7BAQp2-4EwntFj6Nx+be54-fi+gnQmRgT6yS22p=vYugpzA@mail.gmail.com> <CAN-Dau1L_hdRMiGApa7VKuZ0_f5q1NJ-5sHMeg-dtTWa=Tq6bQ@mail.gmail.com> <CAFU7BAS9iMBWkdQF_hwK7squvG9A5f38miS=sWLNns=ZxK4GCg@mail.gmail.com> <CAN-Dau3WswixgY=B9dPwL-hTtxsjm-X-sJ6iXMtpifUAHF12DQ@mail.gmail.com> <CAFU7BASYFEcUgJZUvxi+m4s_GELUQV-2C=UaJ35pBz+zpG1XzA@mail.gmail.com> <CAKD1Yr3OjCsMNM+P2tt9EPrkXDhP+yMptKg-AG3OA1KNbsrqhQ@mail.gmail.com>
In-Reply-To: <CAKD1Yr3OjCsMNM+P2tt9EPrkXDhP+yMptKg-AG3OA1KNbsrqhQ@mail.gmail.com>
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=volz@cisco.com;
x-originating-ip: [173.38.117.78]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: 61cede51-4f2b-4533-0be6-08d77a5ce471
x-ms-traffictypediagnostic: DM6PR11MB4220:
x-microsoft-antispam-prvs: <DM6PR11MB4220F3D570976363B215A4BDCF5F0@DM6PR11MB4220.namprd11.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:9508;
x-forefront-prvs: 0243E5FD68
x-forefront-antispam-report: SFV:NSPM; SFS:(10009020)(396003)(376002)(366004)(39860400002)(346002)(136003)(199004)(189003)(2906002)(186003)(4326008)(5660300002)(8676002)(53546011)(8936002)(81156014)(6506007)(81166006)(26005)(102836004)(790700001)(66946007)(9686003)(64756008)(66556008)(66476007)(71190400001)(66446008)(229853002)(33656002)(71200400001)(76116006)(55016002)(86362001)(76176011)(316002)(7696005)(54896002)(99286004)(74316002)(54906003)(478600001)(52536014)(110136005); DIR:OUT; SFP:1101; SCL:1; SRVR:DM6PR11MB4220; H:DM6PR11MB4137.namprd11.prod.outlook.com; FPR:; SPF:None; LANG:en; PTR:InfoNoRecords; A:1; MX:1;
received-spf: None (protection.outlook.com: cisco.com does not designate permitted sender hosts)
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam: BCL:0;
x-microsoft-antispam-message-info: BtTYa/i0W4Kx3ut7cg+0Zs16dw+VGgrXoh+fxEZexlilhiPOwt2pNlZvh+rC8h0e3JYTTw27wN0QkmEIJZHZS5rsCw4ZUaF7bqfYx64kEtMPOGJeuXALRy4VdzBDL7UdkZ+0u4QdLjMvdp3GKnJ7k4hkqA9+BxdgudbWFD1Wp0wBzX0yv5ryDIe26s+GSklSHz5mY7tSHFZDBWw3gv19hS6pgtx0mybcfqdI+rTD7WPppYvzi316TmnywXEZB4mjTN7y0LvoYpVdZDSp2M74Bo3t7SsZrEiZ0ml/C6YjdkGDKuLcavnwQLbd0Tl0fNfOxk0c4aVQ2VyxJTeVzXloIDGE0qM9O4zfkSVMIb80iTcrPGK2JqUnXpC/9QZ0jTZQz4eag5NEOkQ7m2C4eWNHMTGJvWQr46JDM3j7gJodGzel5uFT/3fury1qAWWWbaZV
x-ms-exchange-transport-forked: True
Content-Type: multipart/alternative; boundary="_000_DM6PR11MB4137A537075D4D90732F7EB4CF5F0DM6PR11MB4137namp_"
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 61cede51-4f2b-4533-0be6-08d77a5ce471
X-MS-Exchange-CrossTenant-originalarrivaltime: 06 Dec 2019 14:59:28.3079 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 5ae1af62-9505-4097-a69a-c1553ef7840e
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: n244DcuKhKsQ2z2sd+AGjuL18094/gbQXldPdZerdHrHEdNB6WQ/x9f3/TK0qRPv
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR11MB4220
X-OriginatorOrg: cisco.com
X-Outbound-SMTP-Client: 173.36.7.17, xch-aln-007.cisco.com
X-Outbound-Node: rcdn-core-12.cisco.com
Archived-At: <https://mailarchive.ietf.org/arch/msg/v6ops/o_16esxorVd4EuaS29aqMWb6RzU>
Subject: Re: [v6ops] [dhcwg] IPv6-Only Preferred DHCPv4 option
X-BeenThere: v6ops@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: v6ops discussion list <v6ops.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/v6ops>, <mailto:v6ops-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/v6ops/>
List-Post: <mailto:v6ops@ietf.org>
List-Help: <mailto:v6ops-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v6ops>, <mailto:v6ops-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 06 Dec 2019 14:59:43 -0000

I agree with Lorenzo. Keep it simple (see previous email that there really should be no work on the DHCP servers to support this capability).

Yes, you could reserve an address, but I don’t see that as required. Note that I had suggested this to the authors before the draft was published as an optimization; I don’t think it should be the norm. And with many servers, you could probably just do this via configuration (i.e., if PRL contains “IPv6-Only” option, override the client identity with a fixed unique name, add a fixed address / reservation for that unique name).


  *   Bernie

From: v6ops <v6ops-bounces@ietf.org> On Behalf Of Lorenzo Colitti
Sent: Friday, December 6, 2019 2:21 AM
To: Jen Linkova <furry13@gmail.com>; Tomek Mrugalski <tomasz.mrugalski@gmail.com>
Cc: V6 Ops List <v6ops@ietf.org>; draft-link-dhc-v6only@ietf.org; dhcwg@ietf.org; Michael Richardson <mcr+ietf@sandelman.ca>
Subject: Re: [v6ops] [dhcwg] IPv6-Only Preferred DHCPv4 option

On Fri, Dec 6, 2019 at 4:14 PM Jen Linkova <furry13@gmail.com<mailto:furry13@gmail.com>> wrote:
"If the pool is explicitly configured with a dedicated IPv4
   address to be returned to IPv6-only capable clients the server MUST
   specify that address as the client's network address and MUST NOT
   verify its uniqueness.

That seems difficult to implement on the server. Why not just return a normal OFFER from the pool? That way, if something unexpected happens and the client sends a DHCPREQUEST for it, the server can hand it out as normal.

The alternative is risky. If the server uses a bogus OFFER value, and some client requests it and the server hands it out, that creates the possibility for misconfiguration or bugs to create really bad outcomes where multiple hosts have the same IP address, or some things on the network (e.g., snooping switches) think that multiple hosts have the same IP address. +Tomek Mrugalski<mailto:tomasz.mrugalski@gmail.com> any thoughts on whether this can be implemented easily and reliably on the server side?

v2.23.0 | Report a Bug | By Email