From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Todd Hayton" Subject: Re: IPv6 multicast forwarding Date: Fri, 24 Oct 2008 09:06:49 -0400 Message-ID: <50a66e370810240606ncb3dcd6gc949b734b1dcf488@mail.gmail.com> References: <50a66e370810231511m10a10ca2oa870e9fbd55f4b0e@mail.gmail.com> <20081024111044.74c15155@varda> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "=?ISO-8859-1?Q?Alejandro_Riveira_Fern=E1ndez?=" , linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: "Pekka Savola" Return-path: Received: from fg-out-1718.google.com ([72.14.220.156]:50001 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751778AbYJXNGv convert rfc822-to-8bit (ORCPT ); Fri, 24 Oct 2008 09:06:51 -0400 Received: by fg-out-1718.google.com with SMTP id 19so963394fgg.17 for ; Fri, 24 Oct 2008 06:06:49 -0700 (PDT) In-Reply-To: Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Oct 24, 2008 at 6:12 AM, Pekka Savola wrote= : > On Fri, 24 Oct 2008, Alejandro Riveira Fern=E1ndez wrote: >>> >>> Let me apologize in advance for the length of this message - it is = long! >>> >>> I'm trying to test out IPv6 multicast forwarding on a 2.6.26 kernel >>> and I'm getting some strange values for the upcall messages from th= e >>> kernel. My code is below, but to give an overview, my setup is as >>> follows: >>> >>> sender ------ ff15::1 -----> [eth1] linux 2.6.26 [eth0] ------> = =2E.. > > Maybe this isn't the bug you're looking for but you shouldn't be usin= g ff1x > multicast addresses in a test like this; ff1x means that the multicas= t group > is of "interface-local scope" and it isn't useful for multicast forwa= rding. > So the kernel might be correct in not installing multicast forwardin= g state > for a group address like this (but if it's a conscious decision, mayb= e the > failure mode should be better). See S 2.7 of RFC4291. > Hey there, thanks for the response! I may be misinterpreting the RFC but I thought ff15::1 was a site-local address. As in I break down ff15::1 as follows - 0xff : identifies the address as multicast 0x15 : 4-bits flags and 4-bits scope where flags =3D 0x1 meaning that the T bit is set as this address is not a permanently assigned address scope =3D 0x5 indicating site-local scope Todd H > -- > Pekka Savola "You each name yourselves king, yet the > Netcore Oy kingdom bleeds." > Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings