# Revision history [back]

I'm not sure if this will help, but I ran into a similar problem with nova networking on Havana, installing on Ubuntu 12.04.

My problem was trying to use the same physical interface for "flat_interface" and "public_interface". That seems to stop the required NAT from happening. When I changed this to use separate interfaces, things started working for me.

My resulting nova.conf network configuration contains the following:

[DEFAULT]
:
# network specific settings
network_manager=nova.network.manager.FlatDHCPManager
firewall_driver=nova.virt.libvirt.firewall.IptablesFirewallDriver
network_size=254
allow_same_net_traffic=False
multi_host=True
send_arp_for_ha=True