Re: [Qemu-devel] [PATCH 0/4] Add nic link up/down emulation to e1000

[Daniel P. Berrange]

On Tue, Dec 09, 2008 at 10:55:39AM +0000, Mark McLoughlin wrote:
> Hi,
>         Here's a small patch set which adds link up/down
> emulation to e1000 via a "set_link" monitor command. This is
> useful for people who want to e.g. test how applications
> and/or the guest OS handles this condition.

It sounds like it could also be useful for people who use bridging of
guests to the LAN on mobile devices. eg, a management tool could 
monitor for when I unplugged my laptop from the ethernet and set the
guest link down. When I then plug it back it, it'd set the link back
up, and the guest (if using NetworkManager or equivalent) would be
able to correctly DHCP a new address. In current scenario with the
guest totally unaware of host link sstatus, they just continue using
the original bogus DHCP address at least until the renew time.

Daniel
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