A very common question from users is how to "bridge" one of their host's ethernet devices so that virtual guests can be connected directly to the physical network (rather than through a libvirt virtual network). This RFE adds a simple virsh command to do exactly that. For example:
virsh iface-bridge eth0 br0
will create a Linux host-bridge device, attach eth0 to it, and move all IP configuration information from eth0 to br0. You can then connect guests to the br0 interface:
This makes the instructions for using "bridge mode networking" orders of magnitude simpler.
There is also an "iface-unbridge" command to revert the interface to its previous un-bridged state.