With this update, legacy routers can now be migrated to an HA router, and vice versa. This allows users to migrate legacy routers to HA routers. To do so, users must unschedule the router from the existing agents, change the 'ha' attribute to 'True', then re-schedule it. Migration from an HA router to a non-HA router is also possible.
Users can use the following commands to migrate a router to and from HA:
neutron router-update --admin-state-up=False <ROUTER>
neutron router-update --ha=True/False <ROUTER>
neutron router-update --admin-state-up=True <ROUTER>