From owner-freebsd-current@FreeBSD.ORG Fri Sep 9 21:49:51 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 7262916A425 for ; Fri, 9 Sep 2005 21:49:51 +0000 (GMT) (envelope-from jd@ugcs.caltech.edu) Received: from regurgitate.ugcs.caltech.edu (regurgitate.ugcs.caltech.edu [131.215.176.97]) by mx1.FreeBSD.org (Postfix) with ESMTP id B78FA43D45 for ; Fri, 9 Sep 2005 21:49:50 +0000 (GMT) (envelope-from jd@ugcs.caltech.edu) Received: by regurgitate.ugcs.caltech.edu (Postfix, from userid 3640) id 377F8E817; Fri, 9 Sep 2005 14:49:48 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by regurgitate.ugcs.caltech.edu (Postfix) with ESMTP id 2103CE815; Fri, 9 Sep 2005 14:49:48 -0700 (PDT) Date: Fri, 9 Sep 2005 14:49:48 -0700 (PDT) From: Jon Dama To: Lars Erik Gullerud In-Reply-To: <20050909111927.I31154@electra.nolink.net> Message-ID: References: <20050901225346.0923E16A41F@hub.freebsd.org> <200509021003.39863.incmc@gmx.de> <20050902164957.GA22097@odin.ac.hmc.edu> <200509072128.04819.incmc@gmx.de> <20050907194130.GA2436@odin.ac.hmc.edu> <20050908220217.X64137@electra.nolink.net> <20050909111927.I31154@electra.nolink.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: freebsd-current@freebsd.org Subject: Re: Default route doesn't change to wireless device (ath0) 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, 09 Sep 2005 21:49:51 -0000 On Fri, 9 Sep 2005, Lars Erik Gullerud wrote: > On Thu, 8 Sep 2005, Jon Dama wrote: > > > > >> Bringing an interface down then back up is usually one of the "try this > >> first" operations when troubleshooting all platforms I normally work on, > >> exactly because it _does_ (normally) clear a lot of state info that you > >> don't want around to confuse you (like the ARP cache and routing table > >> entries). > > > > Yes but surely you'd recognize a difference between a link state change > > and issuing ifconfig ... down > > > > In the latter case, I expect state to be flushed. In the former, I expect > > everything to resume when the link is restored. Imagine having to > > manually reinit your interfaces just because some joker temporary > > unplugged your ethernet cable! > > No, quite the opposite - a link state change is is when you REALLY want > state (particularly ARP) to be flushed. If someone unplugs your ethernet > cable, and the link subsequently returns, you have no way of knowing you > are on the _same network segment_. You may plug out your cable and plug > it into a different network, in which case you do NOT want old ARP > entries to remain. I.e. the new network may use the same IP addressing, > but obviously ARP will point to different macs - in which case you will > get no traffic because your host will not re-ARP IP-addresses for which > it already has a cache entry. ARP cache should _always_ flush on link > state change. > > /leg > To belabor the point, I was talking about the interface configuration. -Jon