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Date: Sun, 18 Jan 2009 11:37:20 +0200
From: Dor Laor <dlaor@redhat.com>
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Subject: Re: [Qemu-devel] Re: [PATCH 1/5] virtio-net: Allow setting the MAC
	address via set_config
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To: qemu-devel@nongnu.org
Cc: Mark McLoughlin <markmc@redhat.com>, kvm <kvm@vger.kernel.org>

Jamie Lokier wrote:
> Dor Laor wrote:
>   
>> What I meant is that if we allow the guest to change his mac address, it 
>> can deliberately
>> change it to other hosts/guests mac and thus create networking problems.
>> Although guest can always mangle packets, maybe it worth enforcing these 
>> macs for the guest.
>>     
>
> Although it can create network problems, sometimes it is also wanted.
>
> I think if you want to restrict the guests's ability to break the
> network by changing its MAC, it would be appropriate to have an option
> to completely lock down the MAC so the guest can't change its MAC at all.
>
>   
That's what I was shooting to.
One example this can be helpful is when kvm is used to run virtual 
servers in a computing
farm like Amazon. You wouldn't like a VM owner to mess your network.