From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: RFC: dsa: add support for multiple CPU ports Date: Wed, 11 Mar 2015 14:30:57 +0100 Message-ID: <20150311133057.GA9601@lunn.ch> References: <20150310190129.GB5636@codeaurora.org> <20150310193151.GE10838@lunn.ch> <20150310204021.GA2740@codeaurora.org> <20150311011802.GA10875@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Florian Fainelli , netdev , Guenter Roeck , Jonas Gorski To: Mathieu Olivari Return-path: Received: from vps0.lunn.ch ([178.209.37.122]:57646 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770AbbCKNeW (ORCPT ); Wed, 11 Mar 2015 09:34:22 -0400 Content-Disposition: inline In-Reply-To: <20150311011802.GA10875@codeaurora.org> Sender: netdev-owner@vger.kernel.org List-ID: > We already have existing interface for eth0/eth1. Maybe we should > consider allowing them to be bridge. User configuration would look like > this: > > brctl addbr br-lan > brctl addif br-lan eth1 > brctl addif br-lan lan1 > brctl addif br-lan lan2 > brctl addif br-lan lan3 > brctl addif br-lan lan4 Think about this from the perspective of somebody how does not know there is a switch. When i look at this, to me it means packets from lan1, lan2, lan3, lan4 and eth1 are bridged together. So we are going to get packets sent out eth1 without a tag on it, and the switch is very likely to drop it, since the port is in a mode which expects a tag. You are not using the brctl command with its normal meaning, which is bad. Configuring this at the bridge layer is also wrong. What conduit a DSA slave interfaces uses is a DSA layer issue. Before we can come up with a nice solution, i think we first need to understand what the switches are capable off. If trunking does work, it is a relatively nice system for the user to configure, in that there is nothing for the user to configure! Assuming the switch can do reasonable load balancing, we also get near optimal usage of the two conduits. I don't know when i will have time to play with this, and if somebody comes along with a better idea, i'm very open to adopting that idea over mine. Andrew