From owner-freebsd-net@FreeBSD.ORG Mon Jul 22 05:22:36 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 F1EFE96 for ; Mon, 22 Jul 2013 05:22:35 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: from mail-vb0-x22a.google.com (mail-vb0-x22a.google.com [IPv6:2607:f8b0:400c:c02::22a]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id B4C3A226B for ; Mon, 22 Jul 2013 05:22:35 +0000 (UTC) Received: by mail-vb0-f42.google.com with SMTP id i3so4492123vbh.15 for ; Sun, 21 Jul 2013 22:22:34 -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=Ct2VfUDf4kYk44plOhlKU8Nf8Yjdt1YiZwgA0T5/yOw=; b=wXT2Cf4Y6CsybR0opZEuTvWV+p69Ut6Ucpg2HertOnEQJaNQpHT5hoOrLAC17ZiUT6 zAceQmhyhmQjR5OA2wJ4HYDxHdWt/7QRgWjXUpK/goGc+l1Xrto4Ths/n7TRd20H0oq4 YSfBmXUv4r9KYQs0eHakJMp0tEzvfXna2XIxg7EcC0OlNUmXqaObS8deTR1p0Q/06OjN xvpe3bSj/eQpDLWJjOwtEP6Kce34xLClVtNeOtm3Rfyih0NfsCtuocbHihmXUOEfzH6/ ZV3wL0s/ermkcpPeaEOHiane56/osNYbE3kKf9sKizQPN2ZmWFUcbw63LoJSamUxhqVX oAwg== MIME-Version: 1.0 X-Received: by 10.58.67.9 with SMTP id j9mr9012160vet.22.1374470554772; Sun, 21 Jul 2013 22:22:34 -0700 (PDT) Received: by 10.221.22.199 with HTTP; Sun, 21 Jul 2013 22:22:34 -0700 (PDT) In-Reply-To: References: <06BA4BD5-BE4E-4184-AFBB-D7FD4B2597D9@your.org> Date: Mon, 22 Jul 2013 01:22:34 -0400 Message-ID: Subject: Re: Duplicate Address Detection misfire? From: Zaphod Beeblebrox To: Kevin Day Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: FreeBSD Net 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: Mon, 22 Jul 2013 05:22:36 -0000 I've further narrowed this down. According to the output: em0 DAD detected duplicate IPv6 address fe80:2::250:56ff:fe2e:45fd: NS in/out=2/1, NA in=0 ... FreeBSD *thinks* it has transmitted one and received 2 solicitations. The packet dump shows two solicitations (which would, if it were not bogus, indicate that another machine was booting at the exact same time trying to use the same link-local address). The question becomes: is vmware duplicating the packet, or is FreeBSD? IE: driver problem with em0 and vmware? I'm not completely sure how to debug this. On Thu, Jul 18, 2013 at 9:21 PM, Zaphod Beeblebrox wrote: > > > > On Sun, Jun 30, 2013 at 10:39 PM, Kevin Day wrote: > >> >> On Jun 30, 2013, at 6:48 PM, Zaphod Beeblebrox wrote: >> >> > I have a FreeBSD 9.1-RELEASE vmware guest running. It is using the >> > "bridged" type of networking with VMWare. It gets it's IPv4 address >> from >> > DHCP (successfully) and then fails to initialize IPv6. The relevant >> > rc.conf is: >> > >> > ipv6_activate_all_interfaces="YES" >> > ifconfig_em0_ipv6="inet6 accept_rtadv" >> > ip6addrctl_verbose="YES" >> > >> > The console output says: >> > >> > em0: DAD detected duplicate IPv6 address fe80:2::20c:29ff:fe0a:3989: NS >> > in/out=2/1, NA in=0 >> > em0: DAD complete for fe80:2::20c:29ff:fe0a:3989 - duplicate found >> > em0: manual intervention required >> > em0: possible hardware address duplication deteted, disable IPv6 >> > >> > And subsequently, em0's nd6 has "IFDISABLED" in it. >> > >> > With wireshark, I see two ICMPv6 neighbor solicitations that are >> identical >> > --- is this the problem? >> > >> > How do I fix this? >> >> Did you copy this VM and have both copies running at once? If so, it >> assigned the same MAC address to each VM. >> >> VMware is suppose to detect this and ask if you "copied" or "moved" the >> VM, and if you say "copied" it will randomly assign a new MAC to the VM. If >> this didn't happen or if you said "moved" when you actually copied it, just >> go in and delete/re-create the network interface in the VM's settings to >> create a new MAC for it. >> >> If that's not the issue, we'd probably need more details about your >> configuration. >> > > To further diagnose, there is only one VM running. To ensure that there > were no duplicates, I reassigned the MAC address in the VMWare > configuration dialogue. Additionally, I tried stopping rtadvd on my router > (no effect) and I tried putting the guest on a "host-only network" > (basically isolated it) --- this clears the problem --- both the link-local > and the static address are assigned. > > Frustrated, I dumped the windows interface that is bridged to the VMWare > guest. When it boots, I see the following: > > 2461 19:24:16.376027000 Vmware_2e:46:fd Broadcast ARP 42 > Gratuitous ARP for 66.96.20.42 (Request) > 2462 19:24:16.388241000 :: ff02::1:ff00:42 ICMPv6 78 > Neighbor Solicitation for 2001:1928:1::42 > 2463 19:24:16.389065000 :: ff02::1:ff00:42 ICMPv6 78 > Neighbor Solicitation for 2001:1928:1::42 > 2464 19:24:16.444130000 :: ff02::16 ICMPv6 130 Multicast > Listener Report Message v2 > 2465 19:24:16.444605000 :: ff02::16 ICMPv6 130 Multicast > Listener Report Message v2 > 2466 19:24:16.594663000 :: ff02::1:ff2e:46fd ICMPv6 78 > Neighbor Solicitation for fe80::250:56ff:fe2e:46fd > 2467 19:24:16.595179000 :: ff02::1:ff2e:46fd ICMPv6 78 > Neighbor Solicitation for fe80::250:56ff:fe2e:46fd > 2753 19:24:22.274728000 Vmware_2e:46:fd Broadcast ARP 42 > Who has 66.96.20.33? Tell 66.96.20.42 > 2754 19:24:22.274902000 Intel_bc:6f:87 Vmware_2e:46:fd ARP 60 > 66.96.20.33 is at 00:0e:0c:bc:6f:87 > > ... and then it goes on to chatter ipv4-wise as expected. Note that there > are two of each packet. Is that normal? The ethernet source of all these > packets is my vmware guest (save the who-has reply that I copied in). > >