openstack-ansible/doc/source/install-guide/configure-networking.rst

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Configuring target host networking

Edit the /etc/openstack_deploy/openstack_user_config.yml file to configure target host networking.

1. Configure the IP address ranges associated with each network in the cidr_networks section:

   cidr_networks:
     # Management (same range as br-mgmt on the target hosts)
     container: CONTAINER_MGMT_CIDR
     # Tunnel endpoints for VXLAN tenant networks
     # (same range as br-vxlan on the target hosts)
     tunnel: TUNNEL_CIDR
     # Storage (same range as br-storage on the target hosts)
     storage: STORAGE_CIDR

   Replace *_CIDR with the appropriate IP address range in CIDR notation. For example, 203.0.113.0/24.

   Use the same IP address ranges as the underlying physical network interfaces or bridges in the section called "Configuring the network". For example, if the container network uses 203.0.113.0/24, the CONTAINER_MGMT_CIDR also uses 203.0.113.0/24.

   The default configuration includes the optional storage and service networks. To remove one or both of them, comment out the appropriate network name.

2. Configure the existing IP addresses in the used_ips section:

   used_ips:
     - EXISTING_IP_ADDRESSES

   Replace EXISTING_IP_ADDRESSES with a list of existing IP addresses in the ranges defined in the previous step. This list should include all IP addresses manually configured on target hosts, internal load balancers, service network bridge, deployment hosts and any other devices to avoid conflicts during the automatic IP address generation process.

   Add individual IP addresses on separate lines. For example, to prevent use of 203.0.113.101 and 201:

   used_ips:
     - 203.0.113.101
     - 203.0.113.201

   Add a range of IP addresses using a comma. For example, to prevent use of 203.0.113.101-201:

   used_ips:
     - "203.0.113.101,203.0.113.201"

3. Configure load balancing in the global_overrides section:

   global_overrides:
     # Internal load balancer VIP address
     internal_lb_vip_address: INTERNAL_LB_VIP_ADDRESS
     # External (DMZ) load balancer VIP address
     external_lb_vip_address: EXTERNAL_LB_VIP_ADDRESS
     # Container network bridge device
     management_bridge: "MGMT_BRIDGE"
     # Tunnel network bridge device
     tunnel_bridge: "TUNNEL_BRIDGE"

   Replace INTERNAL_LB_VIP_ADDRESS with the internal IP address of the load balancer. Infrastructure and OpenStack services use this IP address for internal communication.

   Replace EXTERNAL_LB_VIP_ADDRESS with the external, public, or DMZ IP address of the load balancer. Users primarily use this IP address for external API and web interfaces access.

   Replace MGMT_BRIDGE with the container bridge device name, typically br-mgmt.

   Replace TUNNEL_BRIDGE with the tunnel/overlay bridge device name, typically br-vxlan.

   Note

   Only use global_overrides for networking overrides. Edit all other variable overrides in user_variables.yml.

   global_overrides are not removed from inventory.json and can conflict.

4. Configure the management network in the provider_networks subsection:

   provider_networks:
     - network:
         group_binds:
           - all_containers
           - hosts
         type: "raw"
         container_bridge: "br-mgmt"
         container_interface: "eth1"
         container_type: "veth"
         ip_from_q: "container"
         is_container_address: true
         is_ssh_address: true

5. Configure optional networks in the provider_networks subsection. For example, a storage network:

   provider_networks:
     - network:
         group_binds:
           - glance_api
           - cinder_api
           - cinder_volume
           - nova_compute
         type: "raw"
         container_bridge: "br-storage"
         container_type: "veth"
         container_interface: "eth2"
         ip_from_q: "storage"

   The default configuration includes the optional storage and service networks. To remove one or both of them, comment out the entire associated stanza beginning with the - network: line.

6. Configure OpenStack Networking VXLAN tunnel/overlay networks in the provider_networks subsection:

   provider_networks:
     - network:
         group_binds:
           - neutron_linuxbridge_agent
         container_bridge: "br-vxlan"
         container_type: "veth"
         container_interface: "eth10"
         ip_from_q: "tunnel"
         type: "vxlan"
         range: "TUNNEL_ID_RANGE"
         net_name: "vxlan"

   Replace TUNNEL_ID_RANGE with the tunnel ID range. For example, 1:1000.

7. Configure OpenStack Networking flat (untagged) and VLAN (tagged) networks in the provider_networks subsection:

   provider_networks:
     - network:
         group_binds:
           - neutron_linuxbridge_agent
         container_bridge: "br-vlan"
         container_type: "veth"
         container_interface: "eth12"
         host_bind_override: "PHYSICAL_NETWORK_INTERFACE"
         type: "flat"
         net_name: "flat"
     - network:
         group_binds:
           - neutron_linuxbridge_agent
         container_bridge: "br-vlan"
         container_type: "veth"
         container_interface: "eth11"
         type: "vlan"
         range: VLAN_ID_RANGE
         net_name: "vlan"

   Replace VLAN_ID_RANGE with the VLAN ID range for each VLAN network. For example, 1:1000. Supports more than one range of VLANs on a particular network. For example, 1:1000,2001:3000. Create a similar stanza for each additional network.

   Replace PHYSICAL_NETWORK_INTERFACE with the network interface used for flat networking. Ensure this is a physical interface on the same L2 network being used with the br-vlan devices. If no additional network interface is available, a veth pair plugged into the br-vlan bridge can provide the necessary interface.

   The following is an example of creating a veth-pair within an existing bridge:

   # Create veth pair, do not abort if already exists
   pre-up ip link add br-vlan-veth type veth peer name PHYSICAL_NETWORK_INTERFACE || true
   # Set both ends UP
   pre-up ip link set br-vlan-veth up
   pre-up ip link set PHYSICAL_NETWORK_INTERFACE up
   # Delete veth pair on DOWN
   post-down ip link del br-vlan-veth || true
   bridge_ports br-vlan-veth

Adding static routes to network interfaces

Optionally, you can add one or more static routes to interfaces within containers. Each route requires a destination network in CIDR notation and a gateway. For example:

provider_networks:
  - network:
      group_binds:
        - glance_api
        - cinder_api
        - cinder_volume
        - nova_compute
      type: "raw"
      container_bridge: "br-storage"
      container_interface: "eth2"
      container_type: "veth"
      ip_from_q: "storage"
      static_routes:
        - cidr: 10.176.0.0/12
          gateway: 172.29.248.1

This example adds the following content to the /etc/network/interfaces.d/eth2.cfg file in the appropriate containers:

post-up ip route add 10.176.0.0/12 via 172.29.248.1 || true

The cidr and gateway values must both be specified, or the inventory script will raise an error. Accuracy of the network information is not checked within the inventory script, just that the keys and values are present.

Setting an MTU on a network interface

Larger MTU's can be useful on certain networks, especially storage networks. Add a container_mtu attribute within the provider_networks dictionary to set a custom MTU on the container network interfaces that attach to a particular network:

provider_networks:
  - network:
      group_binds:
        - glance_api
        - cinder_api
        - cinder_volume
        - nova_compute
      type: "raw"
      container_bridge: "br-storage"
      container_interface: "eth2"
      container_type: "veth"
      container_mtu: "9000"
      ip_from_q: "storage"
      static_routes:
        - cidr: 10.176.0.0/12
          gateway: 172.29.248.1

The example above enables jumbo frames by setting the MTU on the storage network to 9000.

Note

If you are editing the MTU for your networks, you may also want to adapt your neutron MTU settings (depending on your needs). Please refer to the neutron documentation (Neutron MTU considerations).

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