[libvirt-users] assign static external IP to container

hello i have a server colocated in a datacenter with several external IP addresses available to use. the physical server is using one of these IPs, and i want to assign another, unused IP to the virtual machine. i thought i could just do this by editing the container's /etc/network/interfaces, setting a static IP address for eth0 much like i did for br0 on the host machine.... but doesn't seem to be working. ifconfig shows eth0 has the external address but i can't resolve any hostnames nor telnet to a direct IP address (no route to host). if i change back to dhcp and let eth0 get an internal address, i can at least access the internet but cannot access the virtual machine from the internet. what is the trick to giving a VM a routable, external IP address? thanks