Neutron uses default settings to determine the type of routers that users are allowed to create. In addition, the settings also specify the number of routers that make up a VRRP group, the default HA network CIDR, and the default network type.
The following settings are specified within the Neutron configuration file at /etc/neutron/neutron.conf, and only need to be modified on the host(s) running the Neutron API service. In this environment, the neutron-server service runs on the controller01 node:
# Enable HA mode for virtual routers. (boolean value)
#l3_ha = false
#
# Maximum number of L3 agents which a HA router will be scheduled
# on. If it is to 0 then the router will be scheduled on every
# agent. (integer value)
#max_l3_agents_per_router = 3
#
# Subnet used for the l3 HA admin network. (string value)
#l3_ha_net_cidr = 169.254.192.0/18
#
# The network type to use...
