From owner-freebsd-net@FreeBSD.ORG Wed Aug 29 13:25:53 2007 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0F05516A418 for ; Wed, 29 Aug 2007 13:25:53 +0000 (UTC) (envelope-from bms@FreeBSD.org) Received: from out2.smtp.messagingengine.com (out2.smtp.messagingengine.com [66.111.4.26]) by mx1.freebsd.org (Postfix) with ESMTP id DCB3913C458 for ; Wed, 29 Aug 2007 13:25:52 +0000 (UTC) (envelope-from bms@FreeBSD.org) Received: from compute1.internal (compute1.internal [10.202.2.41]) by out1.messagingengine.com (Postfix) with ESMTP id 7C1BA26473; Wed, 29 Aug 2007 09:25:50 -0400 (EDT) Received: from heartbeat2.messagingengine.com ([10.202.2.161]) by compute1.internal (MEProxy); Wed, 29 Aug 2007 09:25:50 -0400 X-Sasl-enc: y3WwBGq2M61zZUqFg7fDdBJ2Z01zMdAq6Lb5Qcr/AdFQ 1188393950 Received: from empiric.lon.incunabulum.net (82-35-112-254.cable.ubr07.dals.blueyonder.co.uk [82.35.112.254]) by mail.messagingengine.com (Postfix) with ESMTP id 10D2523363; Wed, 29 Aug 2007 09:25:49 -0400 (EDT) Message-ID: <46D573DD.3080709@FreeBSD.org> Date: Wed, 29 Aug 2007 14:25:49 +0100 From: "Bruce M. Simpson" User-Agent: Thunderbird 2.0.0.4 (X11/20070630) MIME-Version: 1.0 To: Ivan Alexandrovich References: <46D54CC8.4020702@ngs.ru> In-Reply-To: <46D54CC8.4020702@ngs.ru> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: vlan stacking X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Aug 2007 13:25:53 -0000 Ivan Alexandrovich wrote: > Hi > > I'm wondering is anybody using double vlans ("q-in-q", > "vlan stacking", any name you like) on production hosts? > Does it play well with common ethernet device drivers in freebsd > (concerning the frame size) - fxp, em, for example? > > Looks like that almost nobody mentions q-in-q in freebsd > maillists/forums, > except that nesting ng_vlan can be used to implement it. I'm sure you or someone else can come up with a creative solution for Q-in-Q or arbitrary nesting levels. It's not something I use, so, I pass. The mainline code doesn't support it without Netgraph; it would be necessary to allow vlan(4) to be nested. The ether_input() code demuxes 802.1q encapsulation but only 1 level. The reason for this is because the outer VLAN tag got moved into the mbuf pkthdr structure for if_bridge to be able to process it. I can't comment on the netgraph solution however. regards BMS