From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCH] vlan: propogate MTU changes Date: Tue, 07 Oct 2008 00:38:20 +0200 Message-ID: <48EA935C.7090106@trash.net> References: <20081006173024.2741cc01@speedy> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , "David S. Miller" , netdev@vger.kernel.org To: Krzysztof Oledzki Return-path: Received: from stinky.trash.net ([213.144.137.162]:56215 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753243AbYJFWi1 (ORCPT ); Mon, 6 Oct 2008 18:38:27 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Krzysztof Oledzki wrote: > > > On Mon, 6 Oct 2008, Stephen Hemminger wrote: > >> Propogate MTU changes of underlying device to all related VLAN >> devices. >> see: https://bugzilla.vyatta.com/show_bug.cgi?id=3742 > > Not sure about this... Some switches (HP ProCurve for example) allow to > select which vlan accepts jumbo frames and which does not and attach > both to the same port. It is quite useful as you are able to setup one > vlan with jumbo frames dedicated for example to servers connected by > 1G/10G links, and a second vlan with standard 1500 MTU distributed to > non jumbo-aware switches/workstations. Thats why I favour the knob to specify the desired behaviour. Treating a VLAN device as a seperate entity from the ethernet device which just has the same hardware-imposed restrictions seems like a valid view to me.