From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Mac-Address uniqueness Date: Fri, 01 Jun 2007 09:26:16 +0300 Message-ID: <465FBC08.7000102@qumranet.com> References: <465E98B7.5050402@univie.ac.at> <465F72EA.9080608@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Axel Kittenberger To: "H. Peter Anvin" Return-path: In-Reply-To: <465F72EA.9080608-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org H. Peter Anvin wrote: > Axel Kittenberger wrote: > >> Unfortunally all machines detect the same ethernet address >> '52:54:00:12:34:56'. Which you can guess what i means, networking comes >> and goes whatever machine last the ethernet address got hold of from the >> gateway. I tried specifing an ethernet-adress with "-net >> nic,macaddr=$MAC" but this also didn't work through. >> >> For now I just hardseted the mac in all machines to 52:54:00:12:34:57, >> 52:54:00:12:34:58 and so on. >> >> > > This is a Qemuism. I always thought it was dumb, but I guess Qemu > wanted reproducibility over everything. > > IMNSHO it would have been much better to default to a random value > (meaning that all except the bottom 2 bits of the first octet are > random, those bits should be set to 10 binary.) > > That tends to consume dhcp leases quickly, if you start guests often (as I do). Also, some distributions use the mac address as a key for naming interfaces; if it changes, the guest gets confused -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/