From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753468AbaBPS57 (ORCPT ); Sun, 16 Feb 2014 13:57:59 -0500 Received: from mail-pb0-f43.google.com ([209.85.160.43]:40209 "EHLO mail-pb0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753320AbaBPS55 (ORCPT ); Sun, 16 Feb 2014 13:57:57 -0500 Date: Sun, 16 Feb 2014 10:57:54 -0800 From: Stephen Hemminger To: "Luis R. Rodriguez" Cc: netdev@vger.kernel.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, "Luis R. Rodriguez" , bridge@lists.linux-foundation.org Subject: Re: [RFC v2 1/4] bridge: enable interfaces to opt out from becoming the root bridge Message-ID: <20140216105754.63738163@nehalam.linuxnetplumber.net> In-Reply-To: <1392433180-16052-2-git-send-email-mcgrof@do-not-panic.com> References: <1392433180-16052-1-git-send-email-mcgrof@do-not-panic.com> <1392433180-16052-2-git-send-email-mcgrof@do-not-panic.com> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 14 Feb 2014 18:59:37 -0800 "Luis R. Rodriguez" wrote: > From: "Luis R. Rodriguez" > > It doesn't make sense for some interfaces to become a root bridge > at any point in time. One example is virtual backend interfaces > which rely on other entities on the bridge for actual physical > connectivity. They only provide virtual access. > > Device drivers that know they should never become part of the > root bridge have been using a trick of setting their MAC address > to a high broadcast MAC address such as FE:FF:FF:FF:FF:FF. Instead > of using these hacks lets the interfaces annotate its intent and > generalizes a solution for multiple drivers, while letting the > drivers use a random MAC address or one prefixed with a proper OUI. > This sort of hack is used by both qemu and xen for their backend > interfaces. > > Cc: Stephen Hemminger > Cc: bridge@lists.linux-foundation.org > Cc: netdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Luis R. Rodriguez This is already supported in a more standard way via the root block flag. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [RFC v2 1/4] bridge: enable interfaces to opt out from becoming the root bridge Date: Sun, 16 Feb 2014 10:57:54 -0800 Message-ID: <20140216105754.63738163@nehalam.linuxnetplumber.net> References: <1392433180-16052-1-git-send-email-mcgrof@do-not-panic.com> <1392433180-16052-2-git-send-email-mcgrof@do-not-panic.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, "Luis R. Rodriguez" , bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org To: "Luis R. Rodriguez" Return-path: In-Reply-To: <1392433180-16052-2-git-send-email-mcgrof@do-not-panic.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: bridge-bounces@lists.linux-foundation.org Errors-To: bridge-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org On Fri, 14 Feb 2014 18:59:37 -0800 "Luis R. Rodriguez" wrote: > From: "Luis R. Rodriguez" > > It doesn't make sense for some interfaces to become a root bridge > at any point in time. One example is virtual backend interfaces > which rely on other entities on the bridge for actual physical > connectivity. They only provide virtual access. > > Device drivers that know they should never become part of the > root bridge have been using a trick of setting their MAC address > to a high broadcast MAC address such as FE:FF:FF:FF:FF:FF. Instead > of using these hacks lets the interfaces annotate its intent and > generalizes a solution for multiple drivers, while letting the > drivers use a random MAC address or one prefixed with a proper OUI. > This sort of hack is used by both qemu and xen for their backend > interfaces. > > Cc: Stephen Hemminger > Cc: bridge@lists.linux-foundation.org > Cc: netdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Luis R. Rodriguez This is already supported in a more standard way via the root block flag. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sun, 16 Feb 2014 10:57:54 -0800 From: Stephen Hemminger Message-ID: <20140216105754.63738163@nehalam.linuxnetplumber.net> In-Reply-To: <1392433180-16052-2-git-send-email-mcgrof@do-not-panic.com> References: <1392433180-16052-1-git-send-email-mcgrof@do-not-panic.com> <1392433180-16052-2-git-send-email-mcgrof@do-not-panic.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Bridge] [RFC v2 1/4] bridge: enable interfaces to opt out from becoming the root bridge List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Luis R. Rodriguez" Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, "Luis R. Rodriguez" , bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org On Fri, 14 Feb 2014 18:59:37 -0800 "Luis R. Rodriguez" wrote: > From: "Luis R. Rodriguez" > > It doesn't make sense for some interfaces to become a root bridge > at any point in time. One example is virtual backend interfaces > which rely on other entities on the bridge for actual physical > connectivity. They only provide virtual access. > > Device drivers that know they should never become part of the > root bridge have been using a trick of setting their MAC address > to a high broadcast MAC address such as FE:FF:FF:FF:FF:FF. Instead > of using these hacks lets the interfaces annotate its intent and > generalizes a solution for multiple drivers, while letting the > drivers use a random MAC address or one prefixed with a proper OUI. > This sort of hack is used by both qemu and xen for their backend > interfaces. > > Cc: Stephen Hemminger > Cc: bridge@lists.linux-foundation.org > Cc: netdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Luis R. Rodriguez This is already supported in a more standard way via the root block flag.