When a highly available router is created, Neutron creates a VRRP group composed of at least two router namespaces by default. The namespaces are spread across multiple hosts running the Neutron L3 agent, and each runs the keepalived service with its respective configuration. Traffic between the routers uses a dedicated network interface, which is discussed in the following section.
The routers in the VRRP group communicate among one another over a dedicated HA network and interface prefixed with
ha. The default HA network,
169.254.192.0/18, is created automatically by Neutron the first time an HA router is created and utilizes the default tenant network type. Only one network is created per tenant, and it is used by all HA routers created by this tenant. If all HA routers in a tenant are deleted, the HA network will remain and be reused for all other HA routers that get created by the tenant in the future.