From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: MACVLANs really best solution? How about a bridge with multiple bridge virtual interfaces? (was Re: [PATCH] macvlan: Support creating macvlans from macvlans) Date: Sat, 07 Mar 2009 08:30:49 -0800 Message-ID: <49B2A139.8040507@candelatech.com> References: <20090307211527.6e76d0b9.nanog@85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Patrick McHardy , David Miller , netdev@vger.kernel.org, "Eric W. Biederman" , shemminger@linux-foundation.org To: Mark Smith Return-path: Received: from mail.candelatech.com ([208.74.158.172]:42504 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755033AbZCGQbf (ORCPT ); Sat, 7 Mar 2009 11:31:35 -0500 In-Reply-To: <20090307211527.6e76d0b9.nanog@85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org> Sender: netdev-owner@vger.kernel.org List-ID: Mark Smith wrote: > Hi, > > Ben said, > >> I wouldn't deny sending with wrong source mac..ethernet interfaces can >> do this, >> and mac-vlan should look as much like ethernet is possible. >> > > I agree, however there's further things that mac-vlans aren't > currently doing as virtual ethernet interfaces that real ones do. > Unicast ethernet traffic sent out one mac-vlan interface with a > destination address of another mac-vlan interface on the same host > isn't delivered. mac-vlan interfaces, even though they're conceptually > located on the same ethernet segment, are currently isolated from each > other for unicast traffic. > At least for my use, having them all blindly TX is fine. For thousands of interfaces, if you did this right and also delivered all broadcast packets locally (ie, ARP), you will cause a lot of overhead, and unless you are running a patched kernel (or namespaces perhaps), you can't really communicate with yourself over the network anyway using IP. For the behaviour you want, try adding pairs of VETH interfaces and add one end of the veth's to the bridge. Add a physical port to the bridge for egress. Since this can be done, I don't really see any reason to change mac-vlan significantly... If the veth/bridge thing doesn't work, then let us know, as I think that would be a bug. I use a similar-to-veth virtual-device pair in this way and it works fine. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com