From owner-freebsd-isp@FreeBSD.ORG Mon Sep 12 12:51:59 2005 Return-Path: X-Original-To: freebsd-isp@freebsd.org Delivered-To: freebsd-isp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 73C0C16A41F for ; Mon, 12 Sep 2005 12:51:59 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id A8E3643D46 for ; Mon, 12 Sep 2005 12:51:58 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id C73DA5DCC; Mon, 12 Sep 2005 08:51:57 -0400 (EDT) Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 69585-08; Mon, 12 Sep 2005 08:51:56 -0400 (EDT) Received: from [192.168.1.3] (pool-68-161-79-217.ny325.east.verizon.net [68.161.79.217]) by pi.codefab.com (Postfix) with ESMTP id 1787D5DA0; Mon, 12 Sep 2005 08:51:55 -0400 (EDT) Message-ID: <432579F1.4010807@mac.com> Date: Mon, 12 Sep 2005 08:52:01 -0400 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.11) Gecko/20050801 X-Accept-Language: en-us, en MIME-Version: 1.0 To: =?ISO-8859-1?Q?Sten_Daniel_S=F8rsdal?= References: <4322FDC4.8010609@mac.com> <18f601940509110230242e8bfc@mail.gmail.com> <43243677.6020707@mac.com> <43254F76.4000505@wm-access.no> In-Reply-To: <43254F76.4000505@wm-access.no> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Scanned: amavisd-new at codefab.com Cc: freebsd-isp@freebsd.org, aaron.glenn@gmail.com Subject: Re: VLAN interfaces on FreeBSD; performance issues X-BeenThere: freebsd-isp@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Internet Services Providers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Sep 2005 12:51:59 -0000 Sten Daniel Sørsdal wrote: > Chuck Swiger wrote: [ ... ] >> Because you cannot put one NIC into two genuinely distinct layer-2 >> collision domains. Spanning Tree Protocol won't recognize a single NIC >> as a potential connection or loop, depending. > > A vlan should be a seen as a single nic. > On other platforms, STP considers vlans as independant nics. > But would it be multihoming if you are just bridging the vlans? > I thought the essence of multihoming was multiple ip networks to which > it was a member. A VLAN is an abstraction, a way of logically grouping or seperating ports and tagging network traffic with a VLAN header, much as an IP subnet is an abstraction. A NIC is a network interface. It's a physical object. The essence of multihoming is having two (or more) distinct NICs. The most common application for multihoming is where a device performs layer-3 routing between the two or more IP networks, but you could be using SPX/IPX, DECnet, or some other non-IP protocol. You can also do bridging at layer-2, perhaps because the two sides use a different physical layer (Cat-5 ethernet cabling and wireless? Cat5 and thinnet? Cat5 and a dialup PPP link over POTS line, ...etc...) -- -Chuck