From owner-freebsd-net@FreeBSD.ORG Fri Oct 26 11:52:46 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 8168516A420 for ; Fri, 26 Oct 2007 11:52:46 +0000 (UTC) (envelope-from bms@FreeBSD.org) Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by mx1.freebsd.org (Postfix) with ESMTP id 4212013C48E for ; Fri, 26 Oct 2007 11:52:46 +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 87DAA3BE6E; Fri, 26 Oct 2007 07:52:45 -0400 (EDT) Received: from heartbeat1.messagingengine.com ([10.202.2.160]) by compute1.internal (MEProxy); Fri, 26 Oct 2007 07:52:45 -0400 X-Sasl-enc: QJwrQd7Uy5nTDLBm0Cl2E5MOVp/LjcXnt9T1oIElpxLM 1193399565 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 BFD5C22F8; Fri, 26 Oct 2007 07:52:44 -0400 (EDT) Message-ID: <4721D50B.3050909@FreeBSD.org> Date: Fri, 26 Oct 2007 12:52:43 +0100 From: "Bruce M. Simpson" User-Agent: Thunderbird 2.0.0.6 (X11/20070928) MIME-Version: 1.0 To: Nikos Vassiliadis References: <20071026052932.GA72917@pit.databus.com> <200710261040.18817.nvass@teledomenet.gr> In-Reply-To: <200710261040.18817.nvass@teledomenet.gr> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Barney Wolff , freebsd-net@freebsd.org Subject: Re: pppoa connection 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: Fri, 26 Oct 2007 11:52:46 -0000 Nikos Vassiliadis wrote: > flakey fingers... > > On Friday 26 October 2007 10:06:30 Kim Shrier wrote: > >> Other people successfully use this modem to connect to their ISP >> when the ISP accepts pppoe connections and the modem is configured >> as a bridge. Unfortunately, my ISP doesn't support pppoe, only >> pppoa. >> > > The only way to do PPPoA is to have a device that does the DSL and > ATM layers and handles the rest to FreeBSD. Nope - there are devices out there such as the D-link single port DSL-5xxx modems which are able to bridge ethernet to PPPoA, which allows you to *not* use NAT on the device. They do this by running a DHCP client on the outward face, a DHCP server on the inward 'face and allocating itself YourIP+1/24 on that face. Your machine inside then gets assigned YourIP. This is a hybrid form of router/bridging which relies on the IP addressing trick. Obviously the subnet mask is wrong - I haven't figured out if this can be changed in the firmware - which means trouble if you have to route to folk in the same net block. Most consumer DSL 'access devices' force you to use NAT because they don't know how to bridge in this way. However, if you really need to do native PPPoA in BSD, you need an ngATM supported device - /usr/sbin/ppp knows about pppoa devices and should suffice for running it over a single VC. This support was originally added for the Alcatel Speedtouch. Of course if you have an ngatm supported ATM card, and an ATM25-to-ADSL modem (such beasts exist) you can do it that way too - this is how you plug an old Cisco 4xxx into consumer ADSL, by the way. [I'm not sure if MPD groks PPPoA too, but that would let you channel bond with multiple physical circuits.] I should point out that the use of ATM over xDSL is actually part of the G.DMT-lite specs... inquiring individuals can make their own minds up about this and why that happened regards, BMS