From owner-freebsd-net@FreeBSD.ORG Thu Jun 16 07:43:25 2011 Return-Path: Delivered-To: freebsd-net@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6A015106566C for ; Thu, 16 Jun 2011 07:43:25 +0000 (UTC) (envelope-from hrs@FreeBSD.org) Received: from mail.vlsi.ee.noda.tus.ac.jp (sekine00.ee.noda.sut.ac.jp [133.31.107.40]) by mx1.freebsd.org (Postfix) with ESMTP id 19A7E8FC0C for ; Thu, 16 Jun 2011 07:43:23 +0000 (UTC) Received: from alph.allbsd.org (p2237-ipbf904funabasi.chiba.ocn.ne.jp [122.26.37.237]) (user=hrs mech=DIGEST-MD5 bits=128) by mail.vlsi.ee.noda.tus.ac.jp (8.14.4/8.14.4) with ESMTP id p5G7h1SW092884 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 16 Jun 2011 16:43:11 +0900 (JST) (envelope-from hrs@FreeBSD.org) Received: from localhost (localhost [IPv6:::1]) (authenticated bits=0) by alph.allbsd.org (8.14.4/8.14.4) with ESMTP id p5G7gutn005498; Thu, 16 Jun 2011 16:42:58 +0900 (JST) (envelope-from hrs@FreeBSD.org) Date: Thu, 16 Jun 2011 16:42:14 +0900 (JST) Message-Id: <20110616.164214.301126302041762988.hrs@allbsd.org> To: spork@bway.net From: Hiroki Sato In-Reply-To: <4DF9ACCC.5070506@bway.net> References: <4DF9970D.5000505@bway.net> <20110616.145712.10896502890982069.hrs@allbsd.org> <4DF9ACCC.5070506@bway.net> X-PGPkey-fingerprint: BDB3 443F A5DD B3D0 A530 FFD7 4F2C D3D8 2793 CF2D X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Multipart/Signed; protocol="application/pgp-signature"; micalg=pgp-sha1; boundary="--Security_Multipart(Thu_Jun_16_16_42_14_2011_851)--" Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.5 (mail.vlsi.ee.noda.tus.ac.jp [133.31.107.40]); Thu, 16 Jun 2011 16:43:12 +0900 (JST) X-Spam-Status: No, score=6.1 required=14.0 tests=BAYES_50, CONTENT_TYPE_PRESENT, RCVD_IN_PBL, RCVD_IN_RP_RNBL, SPF_SOFTFAIL, X_MAILER_PRESENT autolearn=no version=3.3.1 X-Spam-Level: ****** X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.vlsi.ee.noda.tus.ac.jp Cc: freebsd-net@FreeBSD.org Subject: Re: link-local needed w/static IP and gateway? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Jun 2011 07:43:25 -0000 ----Security_Multipart(Thu_Jun_16_16_42_14_2011_851)-- Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Charles Sprickman wrote in <4DF9ACCC.5070506@bway.net>: sp> > LLA is a MUST for every IPv6-speaking interface, not for automatic sp> > router discovery only. This is because ICMPv6 heavily depends on it. sp> > Without LLA some unexpected and/or inconsistent behaviors can happen, sp> > especially on a router as you experienced. sp> sp> I'm puzzled by why hosts with static IPv6 IPs could communicate with sp> each other. I noticed in some of my netstat output that even though the sp> ff02 multicast network was in the table, it was only bound to the sp> loopback. However I still logged multicast to/from the box. One of the sp> RFCs also noted that multicast is limited in scope to the link-local sp> address, so in theory, not even the host to host ND should have worked. sp> I guess that's what threw me. This is because an L3 address to an L2 address resolution in NDP works in the host-to-host case by chance; addresses in the NDP messages do not have to have a link-local scope and FreeBSD's implementation uses a GUA if it is configured. The host-to-router case doesn't work properly because a router with no LLA never accepts multicast listener discovery messages. You can observe tcpdump output of the host-to-host case and the host-to-router case. The primary difference will be that the unspecified address ("::") is used in MLD report messages in the latter. -- Hiroki ----Security_Multipart(Thu_Jun_16_16_42_14_2011_851)-- Content-Type: application/pgp-signature Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEUEABECAAYFAk35s9YACgkQTyzT2CeTzy3ZfwCfQZY/2jSY28vtpqqJOfoP4usP mmcAljlMNCERokmg2WYEfAgPhuDFUh4= =ERNg -----END PGP SIGNATURE----- ----Security_Multipart(Thu_Jun_16_16_42_14_2011_851)----