openstack-ansible/doc/source/install-guide/overview-network-arch.rst

Network architecture

Although Ansible automates most deployment operations, networking on target hosts requires manual configuration because it varies from one use case to another. This section describes the network configuration that must be implemented on all target hosts.

For more information about how networking works, see network-appendix.

Host network bridges

OpenStack-Ansible uses bridges to connect physical and logical network interfaces on the host to virtual network interfaces within containers. Target hosts are configured with the following network bridges.

• LXC internal: lxcbr0

  The lxcbr0 bridge is required, but OpenStack-Ansible configures it automatically. It provides external (typically Internet) connectivity to containers.

  This bridge does not directly attach to any physical or logical interfaces on the host because iptables handles connectivity. It attaches to eth0 in each container.

  The container network that the bridge attaches to is configurable in the openstack_user_config.yml file in the provider_networks dictionary.

• Container management: br-mgmt

  The br-mgmt bridge is required. It provides management of and communication between the infrastructure and OpenStack services.

  The bridge attaches to a physical or logical interface, typically a bond0 VLAN subinterface. It also attaches to eth1 in each container.

  The container network interface that the bridge attaches to is configurable in the openstack_user_config.yml file.

• Storage:br-storage

  The br-storage bridge is optional, but recommended for production environments. It provides segregated access to Block Storage devices between OpenStack services and Block Storage devices.

  The bridge attaches to a physical or logical interface, typically a bond0 VLAN subinterface. It also attaches to eth2 in each associated container.

  The container network interface that the bridge attaches to is configurable in the openstack_user_config.yml file.

• OpenStack Networking tunnel: br-vxlan

  The br-vxlan bridge is required if the environment is configured to allow projects to create virtual networks. It provides the interface for virtual (VXLAN) tunnel networks.

  The bridge attaches to a physical or logical interface, typically a bond1 VLAN subinterface. It also attaches to eth10 in each associated container.

  The container network interface it attaches to is configurable in the openstack_user_config.yml file.

• OpenStack Networking provider: br-vlan

  The br-vlan bridge is required. It provides infrastructure for VLAN tagged or flat (no VLAN tag) networks.

  The bridge attaches to a physical or logical interface, typically bond1. It attaches to eth11 for VLAN type networks in each associated container. It is not assigned an IP address because it handles only layer 2 connectivity.

  The container network interface that the bridge attaches to is configurable in the openstack_user_config.yml file.