libvirt users - Aug 2014 - NetworkManager and bridged networking

Adam Williamson (adamw) has done a fine job at determining how to get 
bridged networking working with NetworkManager:
https://www.happyassassin.net/2014/07/23/bridged-networking-for-libvirt-with-networkmanager-2014-fedora-21/

According to Adam, he did the work on Fedora 21 whereas I did it on 
Fedora 20.  the undesirable features (problems) I found may be corrected 
on F21 but I believe that they have not been fixed.

While Adam's procedure for creating a bridge definition for 
NetworkManager using the Gnome or nm-connection-editor are basically 
correct.  However, The virt-manager & libvirt do not "like" the
default
names. [*not a show stopper but it should be fixed*] Instead, the the 
bridge definition, use "br0" for the connection name and the device 
name.  For the "slave" definition (the real physical NIC), use the 
<physical_device_name> such as p33p1 or p4p1 or em0 or whatever.  I then 
rebooted the host to make sure everything was clean and the netowrk came 
up fine on br0.

Then, using virt-manager, I took an existing VM, deleted the virtual 
NIC, added a new virtual NIC using br0.  After booting up the VM, you 
need to edit its network configuration to delete the existing definition 
and add a new one pointing to the new virtual NIC.

This works!!!  And on Fedora 20 ... oops, not quite Fedora 20.  This was 
done on a Fedora 20 host which as the updates from fedora-virt-preview 
applied.  I still have a system without the preview updates so I will go 
back and see if it works or it needs the preview updates.

Gene