From owner-freebsd-current@FreeBSD.ORG Tue Mar 29 11:49:38 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2F2E91065677 for ; Tue, 29 Mar 2011 11:49:38 +0000 (UTC) (envelope-from doconnor@gsoft.com.au) Received: from cain.gsoft.com.au (unknown [IPv6:2001:44b8:7c07:5581:266:e1ff:fe0c:8f16]) by mx1.freebsd.org (Postfix) with ESMTP id 92CF88FC0A for ; Tue, 29 Mar 2011 11:49:37 +0000 (UTC) Received: from [10.0.2.78] (ppp208-76.lns1.adl2.internode.on.net [203.122.208.76] (may be forged)) (authenticated bits=0) by cain.gsoft.com.au (8.14.4/8.14.3) with ESMTP id p2TBnQSL043578 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Tue, 29 Mar 2011 22:19:28 +1030 (CST) (envelope-from doconnor@gsoft.com.au) Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: text/plain; charset=us-ascii From: "Daniel O'Connor" In-Reply-To: <20110329113414.GA33138@cicely7.cicely.de> Date: Tue, 29 Mar 2011 22:19:26 +1030 Content-Transfer-Encoding: quoted-printable Message-Id: <6C3B14AB-AB41-4705-84C2-EEFC38656EE9@gsoft.com.au> References: <451C39DA-76B9-4767-9FFC-24F2A182E301@dons.net.au> <0C27BDBF-1F22-4DFD-A1A5-48D0BD1618BC@gsoft.com.au> <71147117-D87B-4F36-9838-238E144BB51F@gsoft.com.au> <20110329113414.GA33138@cicely7.cicely.de> To: ticso@cicely.de X-Mailer: Apple Mail (2.1082) X-Spam-Score: -0.272 () BAYES_00,RDNS_NONE X-Scanned-By: MIMEDefang 2.67 on 203.31.81.10 Cc: Sergey Kandaurov , freebsd-current Current Subject: Re: ipv6 / rtadv problem X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Mar 2011 11:49:38 -0000 On 29/03/2011, at 22:04, Bernd Walter wrote: >> Grr.. I had to reinstall today because I forgot to create a swap = partition and now I can't reproduce the problem :( >=20 > NDP effectively replaces ARP for IPv6. > Like ARP it is also learning by received packets and not only by = direct > query and because of this problems might be unnoticed. >=20 > Unlike ARP NDP is using multicast - instead of sending the inquiry to > a broadcast address each address has a solicatated multicast address = where > the query goes to. > A NIC driver might have broken multicast support, I doub't that's a > problem for your em, but it is more likely that the bug is on the = other > host. > It also could be a problem with multicast aware switches - getting > multicast switiching right isn't an easy task and many implementations > are full of bugs. > If an NDP entry expires a host typically reasks using the unicast = address > and the last known MAC, so once everything seems to run an underlying > multicast problem can live unnoticed for a much longer time. > Currently my own LAN router has a NIC driver with broken multicast > support and nevertheless everything seems to work fine since months > now, but I know the bug is there and that it can bite me each day. >=20 > And unlike ARP NDP is ICMPv6 and not an individual protocol, some > people agressivlely filter ICMPv*, which can easily catch too much. > Especially since many people configuring filter lists are not aware > of those solicitated addresses. Thanks for the information. > My assumption is that the problem is with the other host or switch > network and you just never noticed this so far because this kind of > problem can easily hide for a very long time. Hmm, I have pretty stupid hardware, I am fairly sure none of my switches = understand multicast. If I see it again I will try and get some more information -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C