From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JMb3U-0001NK-Rs for qemu-devel@nongnu.org; Tue, 05 Feb 2008 22:34:36 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JMb3S-0001Mw-AX for qemu-devel@nongnu.org; Tue, 05 Feb 2008 22:34:35 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JMb3R-0001Mm-VB for qemu-devel@nongnu.org; Tue, 05 Feb 2008 22:34:34 -0500 Received: from mail.codesourcery.com ([65.74.133.4]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1JMb3R-0006Pd-Lb for qemu-devel@nongnu.org; Tue, 05 Feb 2008 22:34:33 -0500 From: Paul Brook Subject: Re: [Qemu-devel] Making qemu use 10.0.3.x not 10.0.2.x Date: Wed, 6 Feb 2008 03:34:24 +0000 References: <20080205162206.38J1B.215136.root@eastrmwml22.mgt.cox.net> <200802052129.26282.paul@codesourcery.com> <20080206014031.GA5042@shareable.org> In-Reply-To: <20080206014031.GA5042@shareable.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200802060334.26701.paul@codesourcery.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: andreas.faerber@web.de, Asheesh Laroia On Wednesday 06 February 2008, Jamie Lokier wrote: > Paul Brook wrote: > > > > but make > > > > it configurable on the command line. That way, there are no > > > > surprises ever. The rare people like me with an issue can just pass > > > > a command-line parameter in. > > > > > > The point I was trying to make is that qemu could easily arbitrate the > > > guest network based on how the host is configured. If the host has a > > > 10.0.x.x network (and I suppose if we want to be thorough, a 10.0.x.x > > > route), then it punts to 172.16.x.x (and does the same check) and then > > > tries a couple of 192.168.x.x networks. > > > > I really dislike this kind of guesswork. It makes it very hard to > > debug/reproduce problems, and means you're never really sure what > > qemu is going to do. IMHO One of the really nice features of qemu > > is that it is host independent. > > If it _doesn't_ guess, i.e. uses the fixed default of 10.0.2.x (or any > other), then it's _not_ host independent. Well, obviously anything that involves talking to the host or the outside world is never going to completely host independent. Your case will also break if you run it on a machine with no internet connection. The environment inside qemu is consistent. If you have qemu automagically guess things then the gust OS also has to be capable of coping with things changing underneath it. Paul