# Revision history [back]

### Enabling networking for Nova

I am following the openstack official installation guide online. In this guide, it is assumed that we have a controller machine and one compute machine both of which has two network interfaces. One of the network interfaces is used for public networking and another is for connecting the two together in a private network of range 10.0.0.0/24.

However, in my environment where I am trying to install openstack, the controller and the compute nodes have both only one network interface which has a public access. Both of them can see each other through these interfaces.

After installing Nova, the guide tells me to enable networking for it by following these commands:

# 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


Then I installed and started the openstack-nova-api service on the compute node and tried to run the nova network-create command on the controller. However, I faced the HTTP 500 Error.

# nova network-create vmnet --fixed-range-v4=10.0.0.0/24 --bridge-interface=br100 --multi-host=T


Now I have two questions; 1. What exactly am I doing by setting this parameter in the configuration file of nova? What are these networking configuration used for? 2. How should I change the configuration for my networking environment in which I have only one network interface for each of my nodes?

My operating systems are CentOS and I am trying to install Havana.

### Enabling networking for NovaHow to Enable Networking when both compute and controller have only one network interface which is public.

I am following the openstack official installation guide online. In this guide, it is assumed that we have a controller machine and one compute machine both of which has two network interfaces. One of the network interfaces is used for public networking and another is for connecting the two together in a private network of range 10.0.0.0/24.

However, in my environment where I am trying to install openstack, the controller and the compute nodes have both only one network interface which has a public access. Both of them can see each other through these interfaces.

After installing Nova, the guide tells me to enable networking for it by following these commands:

# 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


Then I installed and started the openstack-nova-api service on the compute node and tried to run the nova network-create command on the controller. However, I faced the HTTP 500 Error.

# nova network-create vmnet --fixed-range-v4=10.0.0.0/24 --bridge-interface=br100 --multi-host=T


Now I have two questions; 1. What exactly am I doing by setting this parameter in the configuration file of nova? What are these networking configuration used for? 2. How should I change the configuration for my networking environment in which I have only one network interface for each of my nodes?

My operating systems are CentOS and I am trying to install Havana.