Original message:
For a new system to develop, I need to know if I can use libvirt for to get (listen) the information that pass trought the lan (vlan) of the each VM.
Marcela's perfect Spanish:
 quiero saber si utilizando esta libreria, puedo utilizar alguna función que me permita capturar los mensajes que se envian aplicaciones paralelas de paso de mensajes que se ejecutan en las máquinas virtuales.
Mike's imperfect translation:
"I need to know if, using this library (libvirt), I can use a function that allows me to capture information sent by applications in parallel to/in addition to information passed by virtual machines"
I'm no expert, but I don't think libvirt has access, via virtual networking, to data sent by applications running in virtual machines. My guess is that such data would be accessible in the same way as with physical machines on a physical network (eg tcpdump?).