Multiple subnets on a single ethernet interface under OpenVZ

You can't simply install OpenVZ and configure your containers to use IP addresses on either block.  By default, OpenVZ will not broadcast ARP packets for IP blocks that it doesn't have a venet interface for - even though you may be bridging your containers to your ethernet device.

Fix:
Edit your /etc/vz/vz.conf file and change the 'NEIGHBOUR_DEVS=detect' to 'NEIGHBOUR_DEVS=all', save and reboot and everything should work beautifully.