Neutron is a virtual network service for Openstack, and a part of
Netstack. Just like OpenStack Nova provides an API to dynamically
request and configure virtual servers, Neutron provides an API to
dynamically request and configure virtual networks. These networks
connect "interfaces" from other OpenStack services (e.g., virtual NICs
from Nova VMs). The Neutron API supports extensions to provide
advanced network capabilities (e.g., QoS, ACLs, network monitoring,
This charm provides central Neutron networking services as part
of a Neutron based Openstack deployment
Neutron provides flexible software defined networking (SDN) for OpenStack.
This charm is designed to be used in conjunction with the rest of the OpenStack
related charms in the charm store) to virtualized the network that Nova Compute
instances plug into.
Its designed as a replacement for nova-network; however it does not yet
support all of the features as nova-network (such as multihost) so may not
be suitable for all.
Neutron supports a rich plugin/extension framework for propriety networking
solutions and supports (in core) Nicira NVP, NEC, Cisco and others...
The Openstack charms currently only support the fully free OpenvSwitch plugin
and implements the 'Provider Router with Private Networks' use case.
See the upstream Neutron documentation
for more details.
In order to use Neutron with Openstack, you will need to deploy the
nova-compute and nova-cloud-controller charms with the network-manager
configuration set to 'Neutron':
This decision must be made prior to deploying Openstack with Juju as
Neutron is deployed baked into these charms from install onwards:
juju deploy nova-compute
juju deploy --config config.yaml nova-cloud-controller
juju add-relation nova-compute nova-cloud-controller
The Neutron Gateway can then be added to the deploying:
juju deploy quantum-gateway
juju add-relation quantum-gateway mysql
juju add-relation quantum-gateway rabbitmq-server
juju add-relation quantum-gateway nova-cloud-controller
The gateway provides two key services; L3 network routing and DHCP services.
These are both required in a fully functional Neutron Openstack deployment.
See upstream Neutron multi extnet
If the port to be used for external traffic is consistent accross all physical
servers then is can be specified by simply setting ext-port to the nic id:
However, if it varies between hosts then the mac addresses of the external
nics for each host can be passed as a space seperated list:
ext-port: <MAC ext port host 1> <MAC ext port host 2> <MAC ext port host 3>
If multiple floating pools are needed then an L3 agent (which corresponds to
a quantum-gateway for the sake of this charm) is needed for each one. Each
gateway needs to be deployed as a seperate service so that the external
network id can be set differently for each gateway e.g.
juju deploy quantum-gateway quantum-gateway-extnet1
juju add-relation quantum-gateway-extnet1 mysql
juju add-relation quantum-gateway-extnet1 rabbitmq-server
juju add-relation quantum-gateway-extnet1 nova-cloud-controller
juju deploy quantum-gateway quantum-gateway-extnet2
juju add-relation quantum-gateway-extnet2 mysql
juju add-relation quantum-gateway-extnet2 rabbitmq-server
juju add-relation quantum-gateway-extnet2 nova-cloud-controller
Create extnet1 and extnet2 via neutron client and take a note of their ids
juju set quantum-gateway-extnet1 "run-internal-router=leader"
juju set quantum-gateway-extnet2 "run-internal-router=none"
juju set quantum-gateway-extnet1 "external-network-id=<extnet1 id>"
juju set quantum-gateway-extnet2 "external-network-id=<extnet2 id>"
When using Open vSwitch plugin with GRE tunnels default MTU of 1500 can cause
packet fragmentation due to GRE overhead. One solution is to increase the MTU on
physical hosts and network equipment. When this is not possible or practical thi
charm's instance-mtu option can be used to reduce instance MTU via DHCP.
juju set quantum-gateway instance-mtu=1400
OpenStack upstream documentation recomments a MTU value of 1400:
Note that this option was added in Havana and will be ignored in older releases.