From owner-freebsd-current@FreeBSD.ORG Fri Jul 15 05:22:23 2005 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4DDA516A41C for ; Fri, 15 Jul 2005 05:22:23 +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 DBA9243D45 for ; Fri, 15 Jul 2005 05:22:22 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 0B7BC5E4F; Fri, 15 Jul 2005 01:22:22 -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 29479-09; Fri, 15 Jul 2005 01:22:12 -0400 (EDT) Received: from [192.168.1.3] (pool-68-161-54-113.ny325.east.verizon.net [68.161.54.113]) by pi.codefab.com (Postfix) with ESMTP id B6EC35D41; Fri, 15 Jul 2005 01:22:11 -0400 (EDT) Message-ID: <42D74806.5040204@mac.com> Date: Fri, 15 Jul 2005 01:22:14 -0400 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.8) Gecko/20050511 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrea Campi References: <20050714182136.071B35D07@ptavv.es.net> <20050714192403.H35071@fledge.watson.org> <20050714185851.GE19351@odin.ac.hmc.edu> <1121368125.83653.12.camel@realtime.exit.com> <20050714193037.GF19351@odin.ac.hmc.edu> <42D6C686.4070407@centtech.com> <20050714202820.GE1064@webcom.it> In-Reply-To: <20050714202820.GE1064@webcom.it> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: amavisd-new at codefab.com Cc: freebsd-current@freebsd.org Subject: Re: Problems with OpenBSD dhclient X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Jul 2005 05:22:23 -0000 Andrea Campi wrote: > picking one random message to answer to... Agreed. :-) > let's not forget Zeroconf (169.254.x.x) address assignment. I have > (admittedly outdated now) patches to howl to make it work that are > waiting on someone to help me finalize them AND most integrate with > appropriate scripts so that things work as expected. This means > removing the autoconfigured address when obtaining a proper address > via DHCP, and vice versa. > > A full solution should IMHO take this into account, too. For the wired case, it's entirely reasonable to respond to a link down/link up combination by doing an ARPOP_REQUEST to the IP address of a router (which quite probably provides the default route) on that interface's associated network, and/or the IP address of the DHCP server which assigned your machine it's IP. If your router/DHCP server still thinks that your MAC address belongs to that IP address, well, the system ought to rely on TCP retransmissions or the design of higher levels to handle a timeperiod of no traffic without needlessly dropping connections by dropping routes, closing open TCP sockets before their time, etc. In other words, an interface link down event should *not* blindly remove or change the assigned IP address on an interface, only a link up event might, and only then after checking via ARP (or a DHCP query, or similar variants). In the meantime, and in the absense of having "multiple default routes" (routes have metrics, can't one use them to prioritize and choose an alternate path if the packets get routed through a link which is down?), it might be nice to pick an alternate default route upon a link-down event. I don't understand the layer-2 aspects of 802.11 wireless stuff modulo the various flavors of WEP and WPA encryption to know whether there is an exact equivalent to ARP, but I'd imagine something could be used to check whether the AP you were just connected to still thinks your machine is what it saw a minute or two ago, before your signal dropped off for a bit... -- -Chuck