From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [RFC] bridge: handle bridge group address per 802.1 standards Date: Tue, 27 Sep 2011 15:01:55 -0700 Message-ID: <20110927150155.4b73fd60@nehalam.linuxnetplumber.net> References: <20110926153630.3959b0ea@nehalam.linuxnetplumber.net> <1317147785.2845.39.camel@bwh-desktop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Ben Hutchings Return-path: Received: from mail.vyatta.com ([76.74.103.46]:51837 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751890Ab1I0WCE (ORCPT ); Tue, 27 Sep 2011 18:02:04 -0400 In-Reply-To: <1317147785.2845.39.camel@bwh-desktop> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 27 Sep 2011 19:23:05 +0100 Ben Hutchings wrote: > On Mon, 2011-09-26 at 15:36 -0700, Stephen Hemminger wrote: > > The Linux bridge code would process all packets addressed to > > the multicast address 01:80:C2:00:00:0X as local and > > and never forward. This may have been correct in the ancient past, but > > reading the relevant standards, the correct behavior is to handle only > > the bridge group address as a special case and leave all other link > > local multicast packets alone. > > I disagree. > > According to my reading, we must filter at least the addresses ending in > 4-D or F, while forwarding of the others should be configurable. > > > Recently there has been some complaints about forwarding (or not) of > > 802.1X EAPOL frames by the bridge. Thanks to Tony Jeffree of the > > 802.1 Bridging Working Group for point me in the correct direction. > > The 802.1X-2010 standard Table 11-1 details how different > > addresses are assigned based on connectivity associations. > > > > Bridge group address: 01-80-C2-00-00-00 > > PAE group address: 01-80-C2-00-00-03 > > Link Layer Discovery 01-80-C2-00-00-0E > [...] > > This table is informative, non normative. The text below refers to > 802.1D table 7-9 (apparently should be 7-10) and 802.1Q table 8-1 as the > sources. > > 802.1D-2004 section 7.12.6, Reserved addresses, says: > > Frames containing any of the group MAC Addresses specified in > Table 7-10 in their destination address field shall not be > relayed by the Bridge. They are configured in the Permanent > Database. Management shall not provide the capability to modify > or remove these entries from the Permanent or the Filtering > Databases. > > In table 7-10 the reserved addresses are those with last digit in the > range 4-F. > > 802.1Q-2005 section 8.6.3, Frame filtering, says: > > Each of the Reserved MAC Addresses specified in Table 8-1 shall > be permanently configured in the Filtering Database in > VLAN-aware Bridges. The Filtering Database Entries for Reserved > MAC Addresses shall specify filtering for all Bridge Ports and > all VLANs. Management shall not provide the capability to modify > or remove entries for Reserved MAC Addresses. > > In table 8-1 the reserved addresses are those with last digit in the > range 4-D or F. There is also a more recent 2011 edition of 802.1Q but it isn't available for free. Let me see if about getting it.