Neutron/DVR/HowTo

Full link: https://www.youtube.com/watch?v=p4BwAjLHd0M

See also https://docs.google.com/document/d/1iXMAyVMf42FTahExmGdYNGOBFyeA4e74sAO3pvr_RjA/edit

DVR Backlog

 * Full DVR backlog
 * DVR backlog excluding fix committed

Fixes that are ready and need code reviews
 * https://review.openstack.org/#/c/105855 (implements migration of legacy router to distributed)

Infrastructure Changes
There is an experimental job which runs tempest tests with DVR enabled by default. As a developer/committer you can use the experimental pipeline to trigger a single-host DVR-backed OpenStack deployment to run Tempest tests (by posting comment 'check experimental').

We would like to convert this soon to non-voting.

Enabling Distributed Virtual Routing Functionality in OpenStack Neutron
This wiki provides information on HowTo Configure and deploy the Distributed Virtual Router functionality in the current OpenStack Neutron implementations.

Configuration
DevStack supports DVR (thanks to this review https://review.openstack.org/#/c/103180/). To kick the tires with DVR on a single node DevStack instance, just set Q_DVR_MODE to 'dvr_snat' and go get a coffee while stack.sh does its magic. If you want to tune things yourself, bear in mind the following:


 * Be sure that your database is at the correct version. There are a number of migration scripts that need to be run using the neutron-db-manage script.
 * Be sure that your firewall or security groups allows UDP traffic over the vxlan port to pass between the hosts


 * Q_PLUGIN=ml2
 * Q_ML2_TENANT_NETWORK_TYPE=vxlan
 * Q_DVR_MODE=dvr_snat

The values for Q_DVR_MODE are disabled, dvr_snat (controller or single node), or dvr (compute node in multi-node).

For reference, here are the settings done...

Dependencies

 * In its initial form, DVR will depend on ml2/ovs and vxlan.
 * Q_PLUGIN=ml2
 * Q_ML2_TENANT_NETWORK_TYPE=vxlan
 * l2pop (see below)

Neutron.conf

 * router_distributed = True
 * This sets the default for new router creation to be DVR.
 * The admin user can convert existing routers to distributed without setting this option to True.

L3 Agent.ini
These options have changed in recent patch set versions


 * Network host (or single node deployment)
 * agent_mode = dvr_snat
 * Compute host
 * agent_mode = dvr

L2 Agent.ini (ml2_conf.ini)
The following options must be configured on all nodes running neutron services.


 * ml2_conf.ini
 * ml2 section
 * append ",l2population" to mechanism_drivers
 * agent section
 * l2_population = True
 * tunnel_types = vxlan
 * enable_distributed_routing = True

Services' Integration
FWaaS and DVR