From owner-freebsd-net@FreeBSD.ORG Tue Jul 23 14:17:03 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 0AA8D4A1 for ; Tue, 23 Jul 2013 14:17:03 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: from mail-vb0-x235.google.com (mail-vb0-x235.google.com [IPv6:2607:f8b0:400c:c02::235]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id BD95C20E4 for ; Tue, 23 Jul 2013 14:17:02 +0000 (UTC) Received: by mail-vb0-f53.google.com with SMTP id p12so5465151vbe.40 for ; Tue, 23 Jul 2013 07:17:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=s+Ua4XyjU0GkOG3ZtYgw3vIdY1PVrVeFEj5CdwoeJhc=; b=sVY5uuwWxNOmGFqylJEM4MhXgSt9OPg7AqO9PhUj3/gP7Ctb1L9i/XaG0x2tnZOWNX bzRJZVpub+96xHUrrlDq/EbVtDvR19hZLNgiiv5vHnnP3k/MOQ+WnYn/79OsZMK5KWa9 QFhHL/HWrdkD9Ng6CckCmJA9bu5dJm4FP0erqIxh5uW7RjL8IkhWIBMscquppKadWoP4 zAJM6HqxVdWArtp8C768wJwmTPsKBBRpcS8SpjQoy1TT0ddY4yMTz281lpAr3rOtbTxn EywV5bMbcYWHh9FRFSFMZ2HwJByTDO8bWrzo4AEl8dKfochHhTaKpvnyfqXZ+koe94eN SPmQ== MIME-Version: 1.0 X-Received: by 10.58.40.16 with SMTP id t16mr11805146vek.64.1374589021862; Tue, 23 Jul 2013 07:17:01 -0700 (PDT) Received: by 10.221.22.199 with HTTP; Tue, 23 Jul 2013 07:17:01 -0700 (PDT) In-Reply-To: References: <06BA4BD5-BE4E-4184-AFBB-D7FD4B2597D9@your.org> Date: Tue, 23 Jul 2013 10:17:01 -0400 Message-ID: Subject: Re: Duplicate Address Detection misfire? From: Zaphod Beeblebrox To: Kimmo Paasiala Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: FreeBSD Net , Kevin Day X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Jul 2013 14:17:03 -0000 Does that mean, then, that the only fix open to some people is to turn off DAD? I have another idea: Require DAD to inspect the sending MAC address. If the sending MAC address is _our_ MAC address, then the packet is not an indication of a duplicate address? On Tue, Jul 23, 2013 at 2:15 AM, Kimmo Paasiala wrote: > On Tue, Jul 23, 2013 at 8:44 AM, Zaphod Beeblebrox > wrote: > > What to do when you don't trust the interface? VMWare is obviously > > emulating the hardware and their interpretation of what the hardware "is" > > is possibly different from ours. > > > > If I boot single-user and tcpdump the interface, I see two transmitted > > solicitations. The kernel claims to have sent one. > > > > My concern: is the vmware interface reflecting the solicitation packet > > because it is a broadcast packet? > > > > To determine this, I've gone over the tcpdump and pcap-filter man pages > to > > look for a way to only dump packets leaving from or arriving at an > > interface. Can this be done? > > > > If VMWare is reflecting the packet back, I'm curious as to how we can fix > > this. > > > > > > That sounds exactly like my experience with DAD misbehaving on my > Zyxel WAP3205 access point. It is reflecting the multicasts (I hope > that's the right term) so that any IPv6 equipment on the wireless > network will think that its address is already in use. For the record, > the client machines in my case are all OS X. Nice to know I'm not the > only one with such problems. > > -Kimmo >