From owner-freebsd-net@FreeBSD.ORG Fri Jan 9 01:04:21 2009 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 54829106566C for ; Fri, 9 Jan 2009 01:04:21 +0000 (UTC) (envelope-from bmw@wezel.com) Received: from tomts20-srv.bellnexxia.net (tomts20.bellnexxia.net [209.226.175.74]) by mx1.freebsd.org (Postfix) with ESMTP id 03C518FC1A for ; Fri, 9 Jan 2009 01:04:20 +0000 (UTC) (envelope-from bmw@wezel.com) Received: from toip4.srvr.bell.ca ([209.226.175.87]) by tomts20-srv.bellnexxia.net (InterMail vM.5.01.06.13 201-253-122-130-113-20050324) with ESMTP id <20090109010420.XCJV1552.tomts20-srv.bellnexxia.net@toip4.srvr.bell.ca> for ; Thu, 8 Jan 2009 20:04:20 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AhUFAPMxZklBX3e3/2dsb2JhbACBbM1uhXU Received: from bas2-toronto63-1096775607.dsl.bell.ca (HELO mg-i1200.home.wezel.com) ([65.95.119.183]) by toip4.srvr.bell.ca with ESMTP; 08 Jan 2009 20:13:22 -0500 Message-ID: <4966A283.4070505@wezel.com> Date: Thu, 08 Jan 2009 20:04:03 -0500 From: Bruce Walker User-Agent: Thunderbird 2.0.0.19 (Macintosh/20081209) MIME-Version: 1.0 To: Peter Steele References: <2ACA3DE8F9758A48B8BE2C7A847F91F2479DF2@polaris.maxiscale.com> <28b9b4180901070039x27a25bb4m6b50c8bfae63e0af@mail.gmail.com> <2ACA3DE8F9758A48B8BE2C7A847F91F2479E9A@polaris.maxiscale.com> <4964CA2E.5090708@wezel.com> <2ACA3DE8F9758A48B8BE2C7A847F91F2479FB0@polaris.maxiscale.com> <2ACA3DE8F9758A48B8BE2C7A847F91F2479FCE@polaris.maxiscale.com> <2ACA3DE8F9758A48B8BE2C7A847F91F2479FD9@polaris.maxiscale.com> <49668C71.4090407@FreeBSD.org> In-Reply-To: <49668C71.4090407@FreeBSD.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: Having problems with limited broadcast 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, 09 Jan 2009 01:04:21 -0000 Bruce M. Simpson wrote: > > The folk who point out that link-local addresses could be used, have > an interesting suggestion which might work for you. Peter, I understand your issue with the (apparent) restriction of the 169.254/16 range, though I'd point out that the IPv4-LL addressing scheme is considered a fall-back plan by most systems implementors. Your systems could look for DHCP first then failing that, drop back to IPv4-LL and get an address. The picky customers would simply be required to supply a DHCP server. Everyone else presumably doesn't care as long as the boxes can communicate. But there's another useful point to pickup from the ZeroConf stuff. I implemented a small standalone IPv4-LLA daemon using libevent, libnet and libpcap. IPv4-LLA needs to muck around with a completely unaddressed interface (like you are doing with your DHCP-lite), sending and listening-for broadcast and directed ARP packets, per RFC 3927. It was trivial to do this in a completely portable way using libpcap and libnet. I'd highly recommend to you that you link those libraries into your Python DHCP-lite app and you will be able to deploy relatively painlessly on any platform that those libraries are ported to. http://sourceforge.net/projects/pylibpcap/ http://pylibnet.sourceforge.net/ Cheers! -bmw