Learning OpenStack Networking - Third Edition

Non-preemptive

In non-preemptive mode, when a router in a VRRP group becomes the master, it continues to operate as the master under normal working conditions. If a backup router is assigned a higher priority later, the active master router will continue to operate as the master until it fails.

As of the Kilo release of OpenStack, Neutron configures each router to act in non-preemptive mode, although this may change in the future. In the event of a failure of the HA network, which is used for communication between the routers, a failed master router may not detect that it has failed. It can continue to operate as a master router, even though another router has been elected master. The lack of connectivity between the routers means that all ...