[libvirt-users] How to configure the container's NIC automatically with an assigned IP address

Dear all, I want to run a TCP/IP application automatically after I start the container using "virsh -c lxc:/// start mycontainer". Does anybody know how to configure the NIC automatically with an assigned IP address? I couldn't find useful information from domain XML format spec and it only talks how to set the mac address (http://libvirt.org/formatdomain.html) . Your response will be highly appreciated. Cheng