From owner-freebsd-net@FreeBSD.ORG Sat Apr 7 15:01:21 2007 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 4930316A403 for ; Sat, 7 Apr 2007 15:01:21 +0000 (UTC) (envelope-from bms@FreeBSD.org) Received: from out4.smtp.messagingengine.com (out4.smtp.messagingengine.com [66.111.4.28]) by mx1.freebsd.org (Postfix) with ESMTP id 21C1E13C4B7 for ; Sat, 7 Apr 2007 15:01:20 +0000 (UTC) (envelope-from bms@FreeBSD.org) Received: from compute2.internal (compute2.internal [10.202.2.42]) by out1.messagingengine.com (Postfix) with ESMTP id E1D502143A3; Sat, 7 Apr 2007 11:01:13 -0400 (EDT) Received: from heartbeat1.messagingengine.com ([10.202.2.160]) by compute2.internal (MEProxy); Sat, 07 Apr 2007 11:01:20 -0400 X-Sasl-enc: Ao4mP6ktSrixDN1beguRGvnJQKD6/iQAd+QkXh6Sb48O 1175958080 Received: from [192.168.123.18] (82-35-112-254.cable.ubr07.dals.blueyonder.co.uk [82.35.112.254]) by mail.messagingengine.com (Postfix) with ESMTP id D5678194F1; Sat, 7 Apr 2007 11:01:19 -0400 (EDT) Message-ID: <4617B23D.1090502@FreeBSD.org> Date: Sat, 07 Apr 2007 16:01:17 +0100 From: "Bruce M. Simpson" User-Agent: Thunderbird 1.5.0.9 (X11/20070125) MIME-Version: 1.0 To: Rajkumar S References: <64de5c8b0704060004s5d2f4416if88f32cc45c77aba@mail.gmail.com> In-Reply-To: <64de5c8b0704060004s5d2f4416if88f32cc45c77aba@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: Spillover routing? 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: Sat, 07 Apr 2007 15:01:21 -0000 Rajkumar S wrote: > Hi, > > I have a low cost 128kbps and a high cost 512 kbps link to internet. > Is it possible to do a "spillover" routing so that the high cost link > is used only when the low cost link is, say, used more than 80%. This feature is almost certainly not going to be present in the base system. What you would need to do to implement this is to configure a part of the kernel to perform bandwidth measurements and make an upcall to bring up the other link in a dial-on-demand style configuration. Add NAT into the mix and it gets even more interesting. I believe pf+altq may have the potential to do this however I could not help you with where to begin re configuring it to do so, so I wish you best of luck in your research. Regards, BMS