From owner-freebsd-questions@FreeBSD.ORG Wed Aug 2 03:03:01 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D92B816A4E1 for ; Wed, 2 Aug 2006 03:03:01 +0000 (UTC) (envelope-from atom.powers@gmail.com) Received: from py-out-1112.google.com (py-out-1112.google.com [64.233.166.176]) by mx1.FreeBSD.org (Postfix) with ESMTP id C350743D4C for ; Wed, 2 Aug 2006 03:03:00 +0000 (GMT) (envelope-from atom.powers@gmail.com) Received: by py-out-1112.google.com with SMTP id b36so1189654pyb for ; Tue, 01 Aug 2006 20:02:58 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=SnD8sTzT/+yvlvRCdWaSsyB5dtY3F2Syoj5DN00V/G66cIdQMwXAiK9LKDCFSMGlFgLC5O1CXE99o35/ygxkdGgqi43bWBxEGT769Z1lVTr5qJ/o5Y7xoMorbIRDEzrX9E/nZqVGcWGLfsM93WlVS4/Q69MRpmoroaQr8MwxSTA= Received: by 10.35.100.6 with SMTP id c6mr620907pym; Tue, 01 Aug 2006 20:02:57 -0700 (PDT) Received: by 10.35.110.6 with HTTP; Tue, 1 Aug 2006 20:02:57 -0700 (PDT) Message-ID: Date: Tue, 1 Aug 2006 20:02:57 -0700 From: "Atom Powers" To: "Malcolm Kay" In-Reply-To: <200608020907.31695.malcolm.kay@internode.on.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <7956f3200607311240g740c949cvbea994374967071f@mail.gmail.com> <200608020907.31695.malcolm.kay@internode.on.net> Cc: Joseph Gleason , questions@freebsd.org, freebsd-questions@freebsd.org Subject: Re: multiple interfaces on same subnet? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Aug 2006 03:03:01 -0000 On 8/1/06, Malcolm Kay wrote: > > I have no personal experience of doing this, but it seems to me > you should be able to achieve your objective by using a specific > netmask with ifconfig rather than the CIDR / notation: > 172.20.0.1/16 -> 172.20.0.1 netmask 255.255.0.1 > 172.20.0.2/16 -> 172.20.0.1 netmask 255.255.0.1 > Creative idea ... even if it's breaking the rules ( so don't do it ). Even if FreeBSD honors these subnets there is no guarantee that any other hosts on the network will. Many systems will refuse to even configure this kind of invalid subnet. Plus, you can't easily scale this to the 10 networks the original poster mentioned and it would be a nightmare to try and figure out how to re-route traffic if one of the next-hop hosts died. (Which was also a goal mentioned in the original post.) Although I've head that IPFW can handle multiple dynamic redirects ( I forswore all other firewalls as soon as I found pf ) you can do it very simply with pf. -- -- Perfection is just a word I use occasionally with mustard. --Atom Powers--