[libvirt] bridge-to-lan interfaces with network type

[Daniel P. Berrange]

On Tue, Feb 03, 2009 at 03:58:38PM +0800, Zhengang Li wrote:
> Hi All,
> 
> The documentation on the libvirt website explains the way to define a 
> bridge to LAN network interfaces with a 'bridge' type. E.g.:
>     <interface type='bridge'>
>       <source bridge='br0'/>
>       <mac address='52:54:00:00:00:11'/>
>     </interface>
> 
> I'm working in a limited environment. Only 'network' type interfaces can 
> be defined for a guest. Is it possible to define a bridge-to-lan 
> interfaces with a 'network' type? The question actually goes to: How to 
> write a network definition xml for libvirt to use as bridge to LAN type 
> NIC in guest?

You are mixing up terminology here. The 'network' type explicitly provides
a connection where the guest only has NAT access to the LAN, while the
'bridge' type connects the guest directly to the LAN. It makes no sense to
ask for 'network' to provide a direct LAN connection, since you'd just
use 'bridge' for that.

If you want to bridge to the LAN, you need to make sure your real eth0
device is part of  a bridge. We have instructions on this setup for
various distros on this page:

  http://wiki.libvirt.org/page/Networking

Under the 'shared physical device' heading

Daniel
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