RETIRED, Tricircle is to provide networking automation across Neutron.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

5.3 KiB


One CentralRegion in which central Neutron and Tricircle services are started, and central Neutron is configured with Tricircle Central Neutron plugin properly. And at least two regions(RegionOne, RegionTwo) in which Tricircle Local Neutron plugin is configured properly in local Neutron.

RegionOne is mapped to az1, and RegionTwo is mapped to az2 by pod management through Tricircle Admin API.

You can use az1 or RegionOne as the value of availability-zone-hint when creating a network. Although in this document only one region in one availability zone, one availability zone can include more than one region in Tricircle pod management, so if you specify az1 as the value, then it means the network will reside in az1, and az1 is mapped to RegionOne, if you add more regions into az1, then the network can spread into these regions too.

Please refer to the installation guide and configuration guide how to setup multi-region environment with Tricircle service enabled.

If you setup the environment through devstack, you can get these settings which are used in this document as follows:

Suppose that each node has 3 interfaces, and eth1 for tenant vlan network, eth2 for external vlan network. If you want to verify the data plane connectivity, please make sure the bridges "br-vlan" and "br-ext" are connected to regarding interface. Using following command to connect the bridge to physical ethernet interface, as shown below, "br-vlan" is wired to eth1, and "br-ext" to eth2:

sudo ovs-vsctl add-br br-vlan
sudo ovs-vsctl add-port br-vlan eth1
sudo ovs-vsctl add-br br-ext
sudo ovs-vsctl add-port br-ext eth2

Suppose the vlan range for tenant network is 101~150, external network is 151~200, in the node which will run central Neutron and Tricircle services, configure the local.conf like this:


enable_plugin tricircle

In the node which will run local Neutron without Tricircle services, configure the local.conf like this:


enable_plugin tricircle

You may have noticed that the only difference is TRICIRCLE_START_SERVICES is True or False. All examples given in this document will be based on these settings.

If you also want to configure vxlan network, suppose the vxlan range for tenant network is 1001~2000, add the following configuration to the above local.conf:


If you also want to configure flat network, suppose you use the same physical network as the vlan network, configure the local.conf like this:


In both RegionOne and RegionTwo, external network is able to be provisioned, the settings will look like this in /etc/neutron/plugins/ml2/ml2_conf.ini:

network_vlan_ranges = bridge:101:150,extern:151:200

vni_ranges = 1001:2000(or the range that you configure)

flat_networks = bridge,extern

bridge_mappings = bridge:br-vlan,extern:br-ext

Please be aware that the physical network name for tenant VLAN network is "bridge", and the external network physical network name is "extern".

In central Neutron's configuration file, the default settings look like as follows:

bridge_network_type = vxlan
network_vlan_ranges = bridge:101:150,extern:151:200
vni_ranges = 1001:2000
flat_networks = bridge,extern
tenant_network_types = vxlan,vlan,flat,local
type_drivers = vxlan,vlan,flat,local

If you want to create a local network, it is recommend that you specify availability_zone_hint as region name when creating the network, instead of specifying the network type as "local". The "local" type has two drawbacks. One is that you can not control the exact type of the network in local Neutron, it's up to your local Neutron's configuration. The other is that the segment ID of the network is allocated by local Neutron, so it may conflict with a segment ID that is allocated by central Neutron. Considering such problems, we have plan to deprecate "local" type.

If you want to create a L2 network across multiple Neutron servers, then you have to speficy --provider-network-type vlan in network creation command for vlan network type, or --provider-network-type vxlan for vxlan network type. Both vlan and vxlan network type could work as the bridge network. The default bridge network type is vxlan.

If you want to create a flat network, which is usually used as the external network type, then you have to specify --provider-network-type flat in network creation command.

You can create L2 network for different purposes, and the supported network types for different purposes are summarized as follows.

Networking purpose Supported
Local L2 network for instances FLAT, VLAN, VxLAN
Cross Neutron L2 network for instances FLAT, VLAN, VxLAN
Bridge network for routers FLAT, VLAN, VxLAN
External network FLAT, VLAN