IETF Logo Mail Archive

RE: DAD question

"Manfredi, Albert E" <albert.e.manfredi@boeing.com> Wed, 15 August 2012 19:37 UTC

Return-Path: <albert.e.manfredi@boeing.com>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D06A321F862B for <ipv6@ietfa.amsl.com>; Wed, 15 Aug 2012 12:37:48 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Level:
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 2on5Ozh34oFV for <ipv6@ietfa.amsl.com>; Wed, 15 Aug 2012 12:37:48 -0700 (PDT)
Received: from stl-mbsout-01.boeing.com (stl-mbsout-01.boeing.com [130.76.96.169]) by ietfa.amsl.com (Postfix) with ESMTP id C556721F8622 for <ipv6@ietf.org>; Wed, 15 Aug 2012 12:37:41 -0700 (PDT)
Received: from stl-mbsout-01.boeing.com (localhost.localdomain [127.0.0.1]) by stl-mbsout-01.boeing.com (8.14.4/8.14.4/DOWNSTREAM_MBSOUT) with ESMTP id q7FJbeqb014227 for <ipv6@ietf.org>; Wed, 15 Aug 2012 14:37:40 -0500
Received: from blv-av-01.boeing.com (blv-av-01.boeing.com [130.247.16.37]) by stl-mbsout-01.boeing.com (8.14.4/8.14.4/UPSTREAM_MBSOUT) with ESMTP id q7FJbdaY014218 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Wed, 15 Aug 2012 14:37:40 -0500
Received: from blv-av-01.boeing.com (localhost.localdomain [127.0.0.1]) by blv-av-01.boeing.com (8.14.4/8.14.4/DOWNSTREAM_RELAY) with ESMTP id q7FJbda8002343; Wed, 15 Aug 2012 12:37:39 -0700
Received: from XCH-MWHT-03.mw.nos.boeing.com (xch-mwht-03.mw.nos.boeing.com [134.57.119.161]) by blv-av-01.boeing.com (8.14.4/8.14.4/UPSTREAM_RELAY) with ESMTP id q7FJbcXj002312 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=OK); Wed, 15 Aug 2012 12:37:39 -0700
Received: from XCH-MW-08V.mw.nos.boeing.com ([134.57.119.191]) by XCH-MWHT-03.mw.nos.boeing.com ([134.57.119.161]) with mapi; Wed, 15 Aug 2012 14:37:38 -0500
From: "Manfredi, Albert E" <albert.e.manfredi@boeing.com>
To: "sthaug@nethelp.no" <sthaug@nethelp.no>
Date: Wed, 15 Aug 2012 14:37:37 -0500
Subject: RE: DAD question
Thread-Topic: DAD question
Thread-Index: Ac17G7J9eq8EQtKBTUKYQEawHXTmBwAAPl2w
Message-ID: <B0147C3DD45E42478038FC347CCB65FE02BCFA4C74@XCH-MW-08V.mw.nos.boeing.com>
References: <502B88DC.3060300@gont.com.ar> <20120815.133810.41706030.sthaug@nethelp.no> <B0147C3DD45E42478038FC347CCB65FE02BCFA4C29@XCH-MW-08V.mw.nos.boeing.com> <20120815.212510.74669626.sthaug@nethelp.no>
In-Reply-To: <20120815.212510.74669626.sthaug@nethelp.no>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-TM-AS-MML: No
Cc: "ipv6@ietf.org" <ipv6@ietf.org>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <ipv6.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipv6>, <mailto:ipv6-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ipv6>
List-Post: <mailto:ipv6@ietf.org>
List-Help: <mailto:ipv6-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipv6>, <mailto:ipv6-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 15 Aug 2012 19:37:48 -0000

sthaug@nethelp.no wrote:

> All I'm saying is that there is nothing wrong,
> standards-wise, in having *one* globally unique MAC address per box.

But I'm disagreeing.

There is a lot wrong with having the same address on multiple ports of a box, when those multiple ports share the same network. This is true both at layer 2 and at layer 3, right?

There are work-arounds, such as ensuring only one port is active, e.g. via STP or whatever.

The Sun scheme worked only under certain circumstances. It would violate standards in certain scenarios.

> Having the same MAC address shared between two (or more) boxes *is*
> wrong, standards-wise. And unfortunately that's exactly what we're
> seeing in practice. Not often, but "often enough" that it may not be
> safe to ignore the possibility.

That's also true.

Bert

v2.23.0 | Report a Bug | By Email