Legacy networking only involves compute nodes. This section covers deployment of a simple flat network that provides IP addresses to your instances via DHCP. If your environment includes multiple compute nodes, the multi-host feature provides redundancy by spreading network functions across compute nodes. Install the packages: # apt-get install nova-network nova-api-metadata # yum install openstack-nova-network openstack-nova-api # zypper install openstack-nova-network openstack-nova-api Configure parameters in the /etc/nova/nova.conf file: Under the [DEFAULT] section: # openstack-config --set /etc/nova/nova.conf DEFAULT \ network_manager nova.network.manager.FlatDHCPManager # openstack-config --set /etc/nova/nova.conf DEFAULT \ firewall_driver nova.virt.libvirt.firewall.IptablesFirewallDriver # openstack-config --set /etc/nova/nova.conf DEFAULT network_size 254 # openstack-config --set /etc/nova/nova.conf DEFAULT allow_same_net_traffic False # openstack-config --set /etc/nova/nova.conf DEFAULT multi_host True # openstack-config --set /etc/nova/nova.conf DEFAULT send_arp_for_ha True # openstack-config --set /etc/nova/nova.conf DEFAULT share_dhcp_address True # openstack-config --set /etc/nova/nova.conf DEFAULT force_dhcp_release True # openstack-config --set /etc/nova/nova.conf DEFAULT flat_interface eth1 # openstack-config --set /etc/nova/nova.conf DEFAULT flat_network_bridge br100 # openstack-config --set /etc/nova/nova.conf DEFAULT public_interface eth1 # openstack-config --set /etc/nova/nova.conf DEFAULT network_api_class nova.network.api.API # openstack-config --set /etc/nova/nova.conf DEFAULT security_group_api nova Edit the /etc/nova/nova.conf file: Add the following keys under the [DEFAULT] section: [DEFAULT] ... 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 share_dhcp_address = True force_dhcp_release = True flat_network_bridge = br100 flat_interface = eth1 public_interface = eth1 Restart the services: # service nova-network restart # service nova-api-metadata restart Start the services and configure them to start when the system boots: # service openstack-nova-network start # service openstack-nova-metadata-api start # chkconfig openstack-nova-network on # chkconfig openstack-nova-metadata-api on